Here's some reading for you
Oil pan
In stock and lifted applications where ground clearance isn't an issue, the stock truck pan will be sufficient.
in lowered or lifted applications used in rock crawling etc, a shorter pan is highly recommended to prevent catastrophic engine damage. The F body oil pan 19212593 is recommended since it fits above the cross member will all common engine mounts.
Another option is the Holley 302-1 Low profile pan, this will tuck above your engine crossmember eliminating the chance of hitting anything with it.
Mounts
There are several different types of mounts available to connect your motor to the chassis, most commonly used are the dirty dingo swap mounts. The adjustable mounts allow for 1/2inch of forward adjustment allowing you to fit a longer transmission like a 4l80e for example, or 2 1/2 inches of rearward adjustment to install your 4l60e or manual etc in the stock location thereby keeping your original driveshafts. All of these mounts allow you to simply bolt your factory “Clamshell” mount to them and then slide over your factory engine mounts on your frame. (Insert Picture)
2wd
Dirty Dingo Motorsports P/N - DD-2550C
4wd
Dirty Dingo Motorsports P/N - DD-2575-4
See Picture
Dingo Sliders
Static 2WD and 4WD – This option is cheaper and when using the stock transmission will still allow you to use your factory driveshafts
Hooker Headers – 12611HKR
Transmission
"Can I keep my transmission" is probably the most commonly asked question after "how much will it cost"
The answer is "Maybe"
For the most part 96-2000 4l60e's mated to a Gen I SBC engine can be adapted to fit the Gen III and Gen IV motors, as can the 4l80e, th400, and almost all older manual transmissions.
I'd personally recommend trying to get a newer automatic with your engine if possible as all 4l60e's from 98 up share a large number of improvements to the casing and internal hard parts.
the early 6.0L engines were also mated to an upgraded 4 speed known as the 4l65e, and most of the improvements in those transmission can be brought back to the older 4l60e's if you need them, including the stronger sun shell and 5 pinion front and rear planetary gear sets.
it's also possible to fit in the newer 6 speed transmissions, though custom mounting and driveshafts may be required
6l80e transmissions share the 32 spline output with the “HD” transmissions of older generations like the 4l80e, and manual transmissions.
The 6l90e 2wd has a 36 spline output that isn’t shared with anything and can complicate driveshaft selection (some quick searching shows that you may be able to swap the 4wd shaft)
6l90e 4wd shares the 29 spline output of the Allison and some Dodge transmissions, this means that you can swap the input shaft on your np241, 261, 243 etc etc to the dodge tcase input, and bolt it up as you would any other transmission
The 6l transmissions will result in the loss of the PRNDL, NSS, and reverse light switches, there are aftermarket interface modules to remedy this, as well as ways to put manual switches in place for the NSS and reverse lights, links to those coming in the future, interfaces are Speartech units
6.0L flex plates are “Flat” compared to the “Dished” 4.8/5.3 Flex plates
To use a 4L80e (Any year) with a 4.8/5.3/6.0 requires the use of a crank spacer 809-12563532 from Jegs.com and 6.0 flex plate, and longer bolts – SUM-704000 (Spacer Kit and Bolts). Spacer goes between the flex plate and crank flange. This spacer and bolts can be found on ANY LS engine that was mated to a 4L80e – FYI cheap and quick way to get these parts. Alternatively ATP Z-270 Flex plate can be used in place of a flat flex plate and spacer. Only for 80e/TH400 Installs (Summit Racing)
ATP Flexplate
To use an Older style 4L60e (96-00 OBS) that was previously bolted up to a SBC, you will use the 4.8/5.3 dished flex plate with the spacer on the OUTSIDE (Between the flex plate and the converter)
To use a Newer style 4L60e 99-07 New Body style that was installed behind a LS engine, simply put on your 4.8/5.3 Dished flex plate on with the shorter length stock bolts with no spacer and bolt the two together, no modification is necessary as these two came mated together from the factory.
When using a older style 60e with your LS, you may have to elongate the flex plate mounting holes to bolt up your converter, this is easiest to do while out of the vehicle on the floor, grind some material off and test fit, continue to do this until you can get all the bolts in, be careful however to not remove too much material as this can cause flex plate failure and the converter bolts could break. See picture
Elongated flex plate holes to fit early 60e
Manual Options
All LS engines are able to bolt to nearly all gm manual transmissions, including the t5, t56, sm465, 5lm60, nv3500 and nv4500 fairly easily, even though the 5.3 was never offered with a manual.
Truck Manual transmissions
You can mate any nv3500, sm465, nv4500 etc to your gen3/4 engine with the following parts
Internal slave style transmission (Inside the Bellhousing)
NFW1050 flywheel
Any stock LS truck clutch set (Typically any 4.8L with a NV3500). Luk 04-201 has been a common choice of clutch.
External slave (Slave mounted outside transmission)
Same as above, but add a Brute 1377c throwout bearing to make up the difference in crank depth
Pilot bearing - CT1082 should fit all LS cranks and should be included with all LS clutch kits
Car Manual transmissions (T-5, T56, TR6060)
T56 should use a flywheel and clutch set compatible with a 98-2002 camaro – P/N for kit - LUK-04-905
The LS7 Clutch set is a common upgrade, something like the Luk 04-905, though many aftermarket options are available as well.
The ls1/ls6 flywheel does not have the raised sections on the outer ring and requires a different clutch and pressure plate such as the LUK 04-173 should work great.
There's only a couple common manuals on this swap, the nv3500 and nv4500 are stock in these trucks and very easy to adapt to the LS. the s10 version of the nv3500 also has a closer ratio, but the transfer case mounting flange is 5 bolts instead of 6 like the full size trucks, so an s10 transfer case has to be used with it on 4wd.
The zf6 may be able to be used, but due to it's size it would require a body lift to fit. They are fairly rare, but came behind the 8.1 so again they'll bolt right up with minimal fuss.
The t56, t56 mangum, and tr6060 all provide 2wd options for 6 speeds, though the tr6060 doesn't have a traditional output shaft, but it can be converted with a t56 magnum rear housing from some place like Tick performance.
There's a 4wd version of the t56 magnum called transzilla and they get pricey.
Fuel
For 88-95 truck that came with the TBI engine, your fuel pump WILL NOT work for you. An LS needs a minimum of 58psi to fire. Thankfully remedying this is easy and straightforward, we’ll start with the fuel pump.
For a 96-00 Model that came with the Vortec 350 engine, your factory fuel pump WILL supply enough pressure for the LS, but again if you are planning on 400whp or more, you will run out of pump quickly, and will need to swap to a Walbro 450 anyway.
You can change the pump in one of two ways, you can pull the bed or drop the tank, My personal preference is to pull the bed, but this is up to you.
To pull the bed, remove your taillights, and pull the wiring out of the taillight holes, at the rear of the bed there are clips to remove the harness, unclip these and lay the taillight harness on the ground. Next unbolt your fuel filler neck by removing the 3 bolts behind the fuel door and pull the filler neck out of the hole and towards the ground. Next there are 8 bed mounting bolts, removing these with a ½’ impact is the way to go, just brap them out of there. If you break one or two don’t sweat this may happen and its not worth your time trying to extract them just use the holes you have left, the box isn’t going anywhere. Next get one of your buddies over to grab the other side of the box, lift it up and pull it back enough to access the fuel tank, set the rear of the box on the bumper (Put some foam or rags down here to avoid scratching your paint) Now if your pump has never been replaced before GM put some sealant down around the fuel pump that you will have to scrape off to access the lock-ring to change the pump.
Early OBS Fuel pump
Next take a hammer and a punch and strike the locking ring in a counter-clockwise direction until you can remove the fuel pump basket, lift it up and out (You will have to maneuver it a little to get the level float out)
Once that is done, now all you must do is just change the pump itself out. For a simple N/A daily driver build with a small cam I recommend the stock fuel pump replacement for a 97 OBS truck, the P/N is AC Delco EP381. For boosted/sprayed/big cam N/A 6.0L builds you will need more fuel, a common replacement is the Walbro 450lph pump – P/N - F90000267 from Summit Racing – You will have to cut the plug off this unit and solder the wires together however.
Remove your old pump from the sending it and the old hose that was on it, slide the hose that came with your kit on (Some kits have hose clamps and some don’t) connect your plug or solder your wires together and that’s it. The Grey wire is the 12V power wire so hook it up correctly to your Walbro pump.
Install your box and re-assemble
Next up is your fuel regulator and fittings – Note that installing a regulator is only required if using a 03-07 Returnless style fuel system covered earlier in this manual.
Fittings
You will need fittings, hose and the regulator, P/N’s are as follows
Metric 16mmx1.5 (Fuel feed – 3/8” pipe) - 9894DBJERL – Summit Racing x1
Metric 14mmx1.5 (Fuel return – 5/16” pipe) - 9894DBHERL – Summit Racing x1
These two fittings adapt the factory hardlines that go into your fuel filter over the AN thread so it can be used
Fuel filter/Regulator and Fittings – Summit sells a nice affordable kit that I like to use – It comes with everything you need – P/N - 03-0263 – Summit Racing x1
Summit Racing Kit
This regulator can be mounted directly on the frame rail after drilling a single hole and bolting it down.
Next you will need some hose and even more fittings
3/8” Pusk-lok hose – P/N - FRA-732006 x1 (This is 20ft, it will be more than enough for you)
3/8” hose x -6 AN female - P/N - FRA-750106-BL x6
Push-lok hose clamps - FRA-999156 x3 (come as a pair, needs to be installed on every connection) Summit
Quick connect push-on -6 fitting - RUS-644113 x1 (to be installed on the fuel rail at the intake) Summit
You will also need this tool to crimp the clamps – P/N - WMR-W83013 x1 Summit Racing
Keep in mind these parts are required only if using a RETURNLESS style fuel rail
Return Style Fuel Rail
This style of rail is easier to adapt to the OBS with less time and money required, and will support more power if that is your goal, you may retain your factory fuel filter and hardlines coming from the tank to the filter, only some fittings are needed to make this work.
I prefer to cut both the return and feed lines with a tubing cutter about 6” after the fuel filter and install compression fittings on the tube to adapt to AN thread
3/8” tube x -6 AN male – P/N - EAR-AT165006ERL x1 Summit Racing (Feed)
5/16” Tube x -6 AN male – P/N - EAR-AT165056ERL x1 Summit Racing (Return)
3/8” Push-lok Hose 20ft – P/N - FRA-750106-BL x1 Summit Racing
3/8” Quick connect fitting – P/N - RUS-644113 x1 Summit Racing (Install onto fuel rail)
5/16” Quick connect fitting – P/N - RUS-644113 x1 Summit Racing (Install onto fuel rail)
3/8’ Hose x -6 AN – P/N - FRA-750106-BL x4 Summit racing (Hose ends)
Push-lok hose clamps - FRA-999156 x2 (come as a pair, needs to be installed on every connection) Summit
You will also need this tool to crimp the clamps – P/N - WMR-W83013 x1 Summit Racing
Miscellaneous Fuel Items/Info
TBI trucks and all Vortec trucks through 97 can run an EP381, vortec stock replacement pump which run around $40 at the parts houses and fit most all carriers. 98-00 OBS trucks will need an LS style pump due to the different sending unit. You may still use a Walbro 450 for this application, however you will need to take the fuel pump “Basket” apart and swap the pump that way.
When adding a new pump, especially a higher volume unit, it's a good idea to upgrade the wiring. What I recommend is to drill a hole in your sending unit, and install a bulkhead fitting like this
P/N - STM-WBF – x1
https://stmtuned.com/products/stm-wire-bulkhead-fitting
This allows you to run larger gauge wiring into the tank without the need to solder inside.
Racetronix Hotwire Kit
Another Item that should not be overlooked is fuel pump wiring, if you are using anything bigger than the stock EP381, you will want to upgrade from the factory 16ga wiring to avoid melting wires and starting fires with the bigger higher amperage draw pump. One kit that will work at an affordable cost is the Racetronix hotwire harness. They’re a Canadian company and will ship fast at a good price. This harness is also plug and play so it can be installed in an hour or so.
Fuel pump hotwire kit – P/N - FPWH-006 x1 Racetronix
Mechanical/Electric Fans
There are several fan options you can choose from so I will highlight them here. In my experience a mechanical fan is fine and doesn’t rob very much power, and so is fine to use in an economical swap situation, if you want to minimize power loss however then the electric fans are the way to go. I also find that these trucks suffer from AC fade parked, at idle because the AC condenser doesn’t have enough airflow through it to cool the charge enough with the mechanical fans, if you are using the electric fans however you can eliminate this problem.
All LS pcm's have the ability to run 2 fans, or a 2 speed single fan via ground relay control.
With some modification, 05-14 NBS and NNBS truck/tahoe/suburban fans can be mounted and fit the 34” radiator fairly well, with some modifications (That’s right you need a factory OBS 34” radiator to use these) I will go over the modifications needed to make these fit later on in the manual.
Another popular option that works with less modification is the 2010 or newer F150/Expedition efans, as they clip to the top of a 34” radiator and fit very well with little modification.
A/C Options
The stock compressors from the 88-95 (R4) trucks and the 96-00 (Sanden 508) can both be made to fit
with the help of some aftermarket bracket kits, these are not cheap but not expensive either
88-95
88-95 trucks came with what is known as the “R4” AC compressor, there is no reason to change it out
when a bracket will make it fit, hoses will also have to be made.
My kit of choice is the ICT Billet R4 compressor bracket P/N - 551585X-3 for $200 American, the quality
is nice, the pulley spacing is correct and the belt doesn’t jump or walk around like some other kits. Belt
P/N with stock 105A alternator is 1105K6. This will change if you have the 140A to 1115K6.
Another option for the R4 is the Dirty Dingo P/N - DD-LS-R4-AC-TR – For $250 American, also a very nice
kit, but more expensive to achieve the same result.
Neither of the two kits mentioned above will clear the EGR on the early 99-02 passenger exhaust
manifolds. The EGR will need to be removed.
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Hoses 88-95 Only
What I ended up doing on all my swaps so far is getting the swap done and driving it to the nearest place
to get hoses built right there (I used Greggs) and it has worked out so far, I will measure the hose specs
and fittings and post them up so you wont have to drive to the store, and remove the old hose and grille
for the hose tech to measure, you would be able to just call in and give them the hose specs and you can
pick it up when its done.
I used a Vintage air blank manifold to get the right ends for new hoses – P/N - VTA-34108-VUG – Summit
Racing
Vintage Air AC Adapter Fitting
Another option is a P/N - UAC-HA10638C hose, I believe this is from a 88-95 6.5L diesel, and will fit in
with no bending or any issues.
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96-00
96-00 Trucks came with the Sanden 508 compressor that is easier to adapt and will not need any hoses
fabricated for them.
First option is the use of the ICT Billet P/N - 551127-3 Bracket kit along with a 551780-3 Alternator kit,
this will allow you to use your factory hoses, but costs more money having to buy 2 brackets. It also sets
the compressor up fairly high. And moves the P/S pump inwards more. Belt P/N when using both kits is
1010K6
ICT Billet - 551127-3
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The Second option is to get a hold of Lextech on the GMT400.com forum or LS1Tech.com, he
sells drivers side compressor mounts that allow you to retain your factory hosing and moving the
alternator over to the passenger side
Lextech’s AC Mount
The last option for AC that some might love and some might hate involves using the factory low
mount LS AC compressor, however it will NOT fit in the engine bay without big modifications, you will
have to cut and box the frame around the compressor to get it to fit in there, if you have plenty of
time/skills and are short on cash then this may be the option for you, however I know nothing about this
process so I will not be going over it.
Exhaust Headers
I do not recommend using mid-length or shorty headers as the stock LS manifolds flow extremely well
and you won’t gain much (If any) performance from them. Long tubes are recommended
4x4-Stock Height or higher
Pacesetter 70-2266 uncoated 1 7/8" primary
Pacesetter 72-c2266 armor coated 1 7/8" primary
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Pacesetter 70-2265 Uncoated 1 3/4" primary
Pacesetter 72-c2265 armorcoated 1 3/4" primary.
Pacesetter 70-2265SS stainless 1 ¾” primary
2WD Stock Height or lower
Schoenfeld 1302LS1 (Comes coated or uncoated, coated is $$)
Speed Engineering Stainless - 25-1025 - Motor Mounts 1" offset further back from factory position to
clear, if you don’t do this, the headers will still fit, but you won’t be happy about the amount of denting
you will have to do to get them to fit.
Throttle Bodies
There aren't a ton of options when it comes to electronic throttle, so it's understandable that many
choose the Drive by Cable option, even though it's not always better.
Drive by cable is perfectly serviceable, and in 96+ trucks can connect directly to the throttle cable and
cruise control of the original truck, simplifying the swap a bit. There are cheap and plentiful options for
large throttle bodies, though they are rarely needed. One popular option is WARR performance.
However, if you're vehicle came originally equipped with drive by wire, you've got a few options as well.
The first, for 99-02 is to convert to drive by cable, rewiring and retuning your ecm. This is especially
advantageous if you didn't get the tb, tac, and pedal with your harness.
03-07 dbc compatibility will depend on the hardware and service numbers on your P59 (blue/green)
ecm
Reference this chart for compatible ecm numbers
From 07+ all engines changed to drive by wire, and no dbc option exists for stock electronics without
converting the engine to gen 3, either through swapping the reluctors and sensors, or using a
lingenfelter convertor.
The stock dbw in all applications is serviceable and responds better to cammed engines than a
comparable sized dbc setup.
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The stock 78mm throttle bodies in both applications are more than capable of flowing all the air needed
in an NA application, and for many boosted applications. I personally wouldn't recommend changing it
out unless your tuner recommends it.
For 99-02 needing larger than stock TB, LS2 throttle bodies from an 05/06 GTO/Corvette will bolt up to a
4-bolt intake and with an adapter harness work with stock electronics. that gives a 90mm TB, and Nick
Williams has a 102 available as well.
If you want to use a larger throttle body for a DBW setup anyway, my recommendation is to go find any
GOLD bladed 4-bolt TB from a Gen4 LS truck engine 07-14 and use that, however this TB has a 6 pin plug
instead of the earlier 8 pin plug, so an adapter is needed to make it work P/N - NAL-SDTRKADPTG –
Summit Racing, however they do retail for $300 CAD.
Miscellaneous Parts
There are several miscellaneous parts you will need to complete this swap, so I will list them here.
LS1 temperature sender – This sensor has 3 wires on it, the plug is the same as a 99-02 TPS plug.
Remove the factory 2 wire temp sender from the front of the drivers side head and install the sensor,
there will be 2 pins right side by side of each other, hook those 2 into the 2 wires from the sensor you
just removed. The last wire remaining will go directly to your gauges – P/N 12551708 AC Delco (Source
this from wherever you can) This is the quickest and easiest way to hook up your temperature gauge,
However I find that this sensor is slightly inaccurate and reads cold on your gauge. It is up to you if you
want to go this route, I will cover other ways to hook up the gauges later on in this guide.
LS1 Temp Sender
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Upper rad hose coupler – Splice this coupler into your upper rad hose, this way you can route the steam
port from the top of the heads into it, this steam hose cannot be blocked off. ICT Billet P/N - ICB-AN627-
20X125 – Summit Racing
Upper rad hose coupler
Oil pressure sender adapter – This fitting will allow you to utilize the factory sender unit that came with
your original 350 and run the oil pressure gauge with it. The sender has NPT threads, but the port at the
back of the intake you need to install this fitting in has metric threads with a sealing washer. Simply
remove the LS engine oil pressure sensor, thread this fitting in and install your factory sender unit and
route the wires. It’s that easy
LS Oil Pressure Adapter
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Evap solenoid block off – Your factory evaporative emissions solenoid is mounted on top of the intake,
the harness we provide will NOT have the plug for it. So, you can either leave it on, or you can remove it
and install this block-off plate P/N – ICT Billet - ICB-551624 Summit Racing.
Evap block-off
EGR Block-Off – This only applies to 99-02 engines with the EGR valve on the passenger exhaust
manifold. There is a hole in the intake behind the TB to plug and the hole on the manifold to plug. There
is a kit available though Speedway motors P/N – 91604001 that blocks off the EGR and the EVAP
solenoid for you. Alternatively you can just buy the EGR intake plug from Speedway – P/N – 91680915
and just weld a plate over the hole in the exhaust manifold. The manifold is cast steel so It welds very
nicely with no need to pre or post heat.
That’s all for the commonly used parts section, optional or more specialized parts will be gone over
later in this manual
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N/A Performance Upgrades
Headers - Starting off with the 4.8/5.3L engines, there are some options for N/A power besides the
camshaft, first is longtube headers of your choice (P/N’s are listed earlier in this manual)
Intakes – While the stock Gen3 truck intake is good and flows very well, there is room for improvement,
the most budget-conscious intake choice will be the Gen4 cathedral-port intake – Also known as a
“TBSS” intake. These can be found on certain Gen3 Trailblazer SS’s (Rare) and any Gen4 4.8/5.3L from
07-14, they are fairly easy to find in the junkyard and on buy and sell groups and flow a significant
amount more than the stock Gen3 intake
Gen3 Intake on the Left and Gen4 on the right
Be conscious of the fact that 07-14 6.0L’s come with an identical-looking intake but have rectangle port
heads, so it will NOT work for you, you want a cathedral-port style Gen4 intake
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TBSS Cathedral Port Intake
Rectangle Port TBSS
While switching over to this style on intake, you will need to be aware of a couple things, firstly is the
change from a 3 Bolt TB to a 4 Bolt TB.
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DBC - If you have a DBC TB and ECM, your next step would be to get a 4-bolt TB from someplace like
WARR Performance, There are many options, but I would recommend anything 92mm or bigger with a 4
bolt mounting flange, just swap over your IAC and TPS and you’re done.
DBW – If you have a DBW intake, your options are more limited and expensive. The first most common
way around this is trying to get the TB that came with the intake, If you bought the intake without one,
then what you will be looking for is ANY TB from a Gen 4 4.8/5.3 in any GM truck from 07-14, if you’re
opting to buy one online an LS3/LS7/L76/L99 style TB with a GOLD throttle blade – GM P/N’s -12605109
12679524, these TB’s will have a 6-pin plug on it instead of 8, so you will need the X-link adapter harness
P/N - NAL-SDTRKADPTG – Summit Racing. For $300 CAD (Not cheap I know) When buying online it is
important to note that any knockoff Chinese TB’s are MUCH cheaper, but do NOT respond as well to IAC
commands and throttle commands, affecting driveability and idle quality if your engine is cammed, I do
NOT recommend the knockoff branded TB’s. I only recommend OEM AC Delco TB’s, while these are
more expensive they cause zero issues. Remember the old adage “Buy once, cry once”? This applies
here.
Nick Williams DBW TB – If for some reason you are looking to get a bigger TB than the 90mm
Gen4/LS3/LS7 TB, Nick Williams has a 103mm and 102mm DBW option for you, P/N - NWP-SD103 –
Summit Racing for $900 CAD, and the 102mm P/N - SD102MMEL. These TB’s also have a 6 pin plug and
will need the X-link adapter to use also – P/N - NAL-SDTRKADPTG – Summit Racing (Same P/N as above)
4-bolt to 3-bolt Adapter – This Is another option if you don’t want to spend the cash on a bigger TB, but
in my opinion, defeats the purpose of swapping the TBSS intake on because of the 76mm TB you will be
putting on (Restrictive) ICT Billet makes the adapter - P/N - ICB-551567 – Summit Racing – for $30 CAD
Injector Plugs - When using the Gen3 truck harness the stock injectors have what is called the “Multec”
style of injector plugs, however your TBSS intake will come with injectors that have the “EV6” Style plug,
to utilize the injectors that came with the intake you will have to swap them over. The advantage of this
is the TBSS intake comes with 36lb/hr injectors and will support any N/A horsepower you can make with
your engine.
LS Injector Plug Styles
Changing the plugs is fairly straightforward, the wires have no specific orientation in the injector plug, all
that is needed is to cut off the old plug, strip the wires and crimp on the new EV6 pins, slide them into
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the new connector body and plug in. You will have to do this to all 8, If the kit is ordered with a TBSS this
will be done for you. EV6 Connector kit P/N – PRF-60131 – Summit Racing
Alternatively you can buy jumper adapters that are simply plug and play for a bit more money – P/N -
ICB-WAINJ32 – Summit Racing
MAP Sensor – The original MAP can be utilized, but you will have to strip some tape and loom off the
harness to gain the extra length required to plug into it. If the kit is ordered with a TBSS intake then this
will already be done for you.
Fuel Rails – All TBSS intakes come with a RETURNLESS style fuel rail, covered earlier in this guide you will
have to swap over to this style using the corvette fuel filter/regulator to utilize these rails, alternatively
you can also install an aftermarket fuel pressure regulator and set it to 60psi – Like this one P/N - TNK-
AFPR1 – Summit Racing - $112 CAD, This regulator will require more fittings to install however, but it
comes with a gauge to easily set pressure.
Hosing – The rest of the existing hosing will work with this intake, the Vacuum brake booster hose and
the PCV valve hose will slide right on, however you will have to get a piece of 3/8” rubber hose and
install in on the port sticking straight up directly behind the TB and route it into the port on the
passenger side valve cover like so:
You Can’t see where the hose is routed to on the passenger valve cover, but it is the only port down there
This Intake swap can be expensive if you have a DBW TB like I did, but you will gain anywhere from 25-
40hp from it, making it worth it in my opinion.
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Camshafts - The most common of all power-adders in the LS world, it’s easy enough to do, but before
you select a cam, you need to have a power goal in mind.
I will not recommend a specific cam – there are too many variables, however after buying our swap kit I
will help you spec a cam for your build, and pre-install it for you. I will also show you how to swap a cam
out in this guide, this can be easily done requiring only one special tool to make it happen.
A cam swap is easiest done with the engine on a stand but can be done in the vehicle if you wish to
upgrade later on. Both ways are very similar, just doing it in the truck there is less room to work and will
require the removal of the radiator.
Start with removing the front accessories (Water pump, Power steering/Alternator bracket, serpentine
belt) Remove the valve covers and remove the entire rocker arm assembly from both sides along with
the pushrods, set these aside on something clean for later on.
Remove the harmonic balancer bolt (I like to change this out when I remove it, and you will have to cut
up the old one to use the balancer puller that I recommend) GM P/N for the new bolt is – 12557840, you
can get this at any GM dealer nearest to you, some aftermarket parts store may even be able to get it
also. This bolt can be stubborn, I recommend the use of a ½” air or electric impact as if you use a breaker
bar you will simply spin the engine over instead, if your impact can’t get it out, another trick I like to use
is to simply heat the head of the bolt with either an acetylene torch or even a small MAP gas torch, don’t
go crazy otherwise you will melt the crank seal, just enough to get the bolt out. You will need a torch of
some sort later to install the balancer, so I recommend getting a MAP gas torch anyway.
Cut the head of your old balancer bolt off and grind a slot in it, take a flathead screwdriver and test-fit it
in the slot until the screwdriver fits nicely in the slot, screw It a couple threads down the crank hole and
install your balancer puller, I bought my puller from Canadian Tire P/N – 77139 “Chrysler Harmonic
Balancer Puller”. You can now use the shortest puller rod in the kit, use an impact or a ratchet to
remove the balance and then screw out the balancer bolt with your screwdriver. Alternatively, if you
have an extra LS pushrod, you can use that as a pusher rod on the removal tool.
Remove your bolts for the front cover, and the cover itself, install a bolt back into the crank snout and
turn the engine over until the dot on the crank gear lines up with the dot on the cam gear, this means
you are set at TDC 1 and will have an easier time lining up the marks after you install the new cam. Now
remove the cam gear bolts and the cam, let the timing chain fall onto the crank gear, remove the bolts
from the cam retaining plate, and inspect the seal behind the plate, this provides oil to your lifters and is
very important for it not to be damaged in any way. Next up is cam removal, thread the long 8mm bolts
that came from your water pump into the end of the cam and spin the cam a couple times, if you’re
lucky this will push the lifters up into their plastic holders and they will stay there, although I find this
risky, if you remove the cam and a lifter falls down before you can put the new cam in, then you will
have to pull the head off to re-install it. So if you are doing this on a stand then simply flip the engine
over 180 degrees, spin the cam and pull it out carefully, then install the new cam. If you are doing this in
the vehicle, then you will need to buy 2 5/16” wooden dowel rods from Canadian tire, give the cam a
spin and install the dowel rods into the oil passages behind the cam retainer plate, this will hold the
lifters up for you. Remove the cam and swap a new one in.
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Re-install the cam retainer plate with a new gasket or the old one if it was in good enough shape. TQ the
bolts to spec.
LS Torque Specs (4.8/5.3/6.0L)
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All the specs you will need to completely tear down an LS and put it back together are here.
Next take your timing gear and wrap your timing chain around it, make sure the crank gear timing dot is
still facing straight up towards the cam, this is a bit tricky, but you will need to install the cam gear so
that the dot on it lines up exactly with the cam gear, you cannot be even one tooth out or this will cause
timing issues. The cam gear only goes onto the cam one way also. Once you have them lined up, snug up
the bolts on the cam and spin the engine over and check to make sure the timing dots are aligned again,
do this once more to verify.
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This is an engine with the oil pump removed for clarity, you can clearly see how to timing marks should
be aligned, you can remove the oil pump if you like but It can be done without.
Next you can torque the cam gear bolts and install the timing cover with or without a new gasket. Re-
assemble the rest of the engine, you will probably need new water pump gaskets are they never seem
to come off in one piece.
Cylinder heads – If you are running a 4.8/5.3L your head upgrade options are limited at best, but there
are a few notable aftermarket/Factory upgrades for this engine.
Factory heads 862/706 – Depending on the year of your 4.8/5.3, you will have either 862 or 706 heads,
valve size, runner length, and combustion chamber size are all identical, however the 862 has a slightly
rougher casting than the 706 heads, meaning slightly less flow. 862’s Typically came on 99-02 engines
while 706’s came on 03-07 engines. Some 706 heads made by Castech had the possibility to crack
around the head bolts and leak small amounts of coolant into your engine, so watch out for this.
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Castech Logo
Basically, if you want to stick with the 706/862 heads, you have 2 options, you can get the heads ported
to gain some airflow and power, or you can get the machine shop to mill down the deck surface. This
will effectively increase compression ratio depending on how much was taken off.
Trick Flow 220 – These are a 20-30 hp improvement over the factory 4.8/5.3 heads, although they are
expensive. Your decision.
LQ4/LQ9 Head Swap
There are a couple more head upgrades for this engine than the 4.8/5.3L
862/706 Head swap. While these heads have smaller valves and flow less than the factory 317
heads, this swap will bump your compression up from 9.5:1 to 11:1, you will have to run 91
octane minimum and you will not be able to take full advantage of this upgrade, if you run 93
this will not be a problem. This simple swap gains 40-50 hp
243/799 Head swap – 243 Heads ONLY came on 97-00 LS1 cars (Camaro/Corvette) they are hard
to find and are usually expensive. 799 Heads came on all Gen4 4.8/5.3 LS engines, they are
almost identical heads, so don’t let anyone fool you with “243’s are better” They are not. This
upgrade does the same thing as the 862/706 head swap, the only difference looking at the
power curve is that 243/799 heads loose out on TQ through the whole power band and make
10-15 more hp from 6000-6500rpm. Which heads you choose is up to you based on
goals/budget
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Turbo/Supercharger
Wanting to make big power? This is the way to do it. Factory junkyard LS’s can make upwards of 600whp
safely and reliably with stock bottom ends/heads and a set of valve springs. You will have to do fab work
or buy kits for the Hot/cold sides and install wastegates and BOV’s, there is a bunch of work involved.
More on this after we complete our first turbo build.
Engine Tear-Down/Re-assembly
More on this later when we have pictures
Removing Your old SBC
Also more on this when we have pictures
Installing Your LS
First up will be mating your new/old transmission to your LS. If you are using an older 4L60E then you
will have to utilize the .400” spacer plate and longer bolts mentioned earlier in this guide with the
spacer on the outside.
(Insert Pic)
Using an 80e of any year you will use the FLAT 6.0L flexplate with the spacer between the crank and the
flexplate with longer bolts.
Manual swaps and P/N earlier in this guide
Push the engine/trans together and wiggle them until the bellhousing bottoms out on the rear of the
engine DO NOT PUT THE BOLTS IN AND “DRAW” THEM TOGETHER if you try that and they weren’t
properly aligned you will push the converter into the transmission pump and break it. This will result in
no gears at first start-up – And a costly rebuild. Next is to check converter to flexplate clearance, you
may pull the converter into the flexplate as long as the gap is no bigger than 3/16” of an inch (I use a
3/16” drill bit to check this) if the spacing is bigger than that you may use 3/8” or M10 washers between
the converter and flexplate to achieve the correct gap. Install the bolts into the converter with some
blue locktite and TQ to 44ft-lbs. Don’t install the starter yet.
Temp Sender
Next you need to make some decisions, If you want to use the LS1 temp sensor to run your temp gauge
and give the ECM temp feedback go ahead and install it now. If not you will have to drill and tap the
back of the passenger head or the top of the water pump. If you opt for the cylinder head, remove the
metric allen head plug from the head, and drill the hole out to 37/64” with the appropriate drill bit. To
minimize shavings tip your bit in a tube of grease, drill a little, wipe off the grease/filings and repeat until
you’re done. Next get a 3/8” NPT (National Pipe Thread) tap and tap the hole out also using the grease
method. Install your factory temp sender from your old SBC in this hole (Don’t forget the thread tape)
Alternatively you can drill and tap the top of the water pump also. The last option is to install a hose
coupler in the upper rad hose and install the sender there. (Coupler is listed earlier in this guide)
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Steam Line
You may have noticed a small ¼” hose coming from below your intake from the “Steam Ports” on top of
the heads. You CANNOT just block this line off, coolant/air needs to flow out of the top of this engine
back into the system. You have several options here, the cheapest way is to again drill and tap the top of
the water pump with a 21/64” drill bit and tap it out with a 1/8” NPT tap, also using the grease method.
Install a 1/8” Male NPT x ¼’ hose barb fitting here. You will install the hose after you install the engine
and intake. Alternatively you can also use a hose barb splicer in the upper rad hose.
Some replacement 454 sized radiators have a spare port on the passenger side below the rad cap (Not
the nipple directly under the cap) you may use fittings and adapt into that if you like.
Oil Pressure Sender
You may utilize the adapter fittings listed earlier to plug directly into the port behind the intake, or use
the factory 99-02 Sender unit also listed earlier, OR you can remove the Oil cooler block-off plate from
the oil filter housing/oil pan. And drill and tap it to accept your sender unit. Again this is a 21/64” drill bit
and a 1/8NPT tap. Use the grease method. Install your sender here if you don’t want to spend money on
adapters.
Drilled and tapped Oil cooler plate
Engine Mounts
If you had a factory V6 engine, you will have to remove the engine mounts on the frame and change
them to V-8 ones. If you had a factory V8 skip this part. on a 4wd this is a cakewalk, if you have a 2wd,
this can be a pain. You may have to remove the lower control arms or at least the spring to make this
happen, the new V8 mounts will bolt right in. Summit Racing Mounts - ANI-2621. You may also add a
polyurethane insert if you choose Summit Racing - ENS-3-1121G.
Once you have the motor mounts in you can remove the original engine mounts from your LS and install
your adapter mounts of choice. I prefer Dirty Dingo or the hooker mounts, but that is my preference.
Next you will have to modify the “Clamshells” from your old SBC. On the backside of these there is a
“Hump” that you can either cut out with a torch or grind flat. Neither affect integrity and either way is
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fine. On the passenger mount you will have to cut out a notch in the mount or cut the boss on the
engine off. This boss used to hold the transmission lines but you wont need that anymore. Once that is
completed you may bolt both of your clamshells.
Install
Remove your intake if you already haven’t, this will aid in install and allow you to install the harness
grounds at the rear of the engine.
Install the engine using the original clamshell mounts and install the mount bolts
