My L03 Plans & Some Questions

[DeuceRooster]

Wanting to get some more power out of my L03 (305 tbi) using some stuff that I already have laying around my shop. Looking for some advice.

Current setup on my 1990 C1500 SWB 3.42s & 700R4
-Delco EP241 Fuel Pump w/fresh filter
-Mid Length 1-5/8" Headers With FlowTech Y-Pipe (nicer merge than factory) and a single 3" outlet
-3 Wire (Heated) o2
-25% Underdrive Crank Pulley

Otherwise everything is completely stock. Here are items I have laying around from past builds.

-Fully reconditioned 081 (305 TPI) Heads WITH 1.94 Intake and 1.50 Exhaust valves (3 angle valve job as well)
-New Summit K-1102 Camshaft 204/214 0.421/0.444 and 112LSA (NOS Made in USA)

My L03 is in great shape with excellent compression. I am NOT currently interested in engine swapping it. I would like to use the K-1102 cam I have unless it's just not work fooling with. I plan to use my truck for a weekend driver around town.

Where do I go from here? I would like to keep my total investment from this point on under $1000

I would really like to use the 081 heads and the K-1102 camshaft on the truck if they would be beneficial. What smaller mods should I do first to prepare for them?

Things I've been looking at are Adjustable FPR for the TBI, "Salad Bowl" or Open Element?, TBI Pod Spacer, Aftermarket intake? Do I need any of these? I plan to purchase EBL Flash-II and learn to tune it myself.

I know many of you have years of experience and a lot of trial and error with these trucks. Please guide me in the right direction lol

 

[L31MaxExpress]

The cam is benificial the heads not so much the heads.

 

[DeuceRooster]

The cam is benificial the heads not so much the heads.

Thank you for the insight.

If I add only the cam to the mods I already have then would an aftermarket intake be beneficial? I was looking at maybe the Holley Pro-Jection 300-49 or the Edelbrock 3704. Or would I be better off with carb intake and a TBI to carb adapter? Or no gains to be had there?

 

[DeuceRooster]

I suppose i'll just move forward with the 1102 cam and re-use the stock intake for now and learn to tune with EBL Flash device. Not much going on in here with TBI systems it seems.

 

[98 Nitro]

Well you could buy EQ 305 Vortec heads and use the GMPP TBI to Vortec intake or a Vortec carb intake with adapter.

 

[Schurkey]

-Delco EP241 Fuel Pump w/fresh filter

Pretty sure that's the pump I have on my '88 K1500 5.7L.

-Mid Length 1-5/8" Headers With FlowTech Y-Pipe (nicer merge than factory) and a single 3" outlet
-3 Wire (Heated) o2

Don't forget the modern, high-flow (honecomb, monolithic) catalyst.

-25% Underdrive Crank Pulley

Asking for cooling system, alternator, and PS problems.

-Fully reconditioned 081 (305 TPI) Heads WITH 1.94 Intake and 1.50 Exhaust valves (3 angle valve job as well)

NOTHING special about a 3-angle valve job.

GM never put 1.94 valves onto a 305. Far as I know, they never got anything bigger than 1.85.

-New Summit K-1102 Camshaft 204/214 0.421/0.444 and 112LSA (NOS Made in USA)

Not thrilled about a flat-tappet cam, but if you already own it...

Where do I go from here? I would like to keep my total investment from this point on under $1000

Wild guess with no evidence: You could spend the entire Grand on safety items--steering, suspension, and brakes.

Things I've been looking at are Adjustable FPR for the TBI,

Doesn't need to be adjustable. Needs to provide correct fuel pressure. Kinda guessing 11--13 psi would be TOTALLY adequate. Most folks want to be towards the upper end of the fuel pressure spec of 9--13 psi.

"Salad Bowl" or Open Element, TBI Pod Spacer, Aftermarket intake? Do I need any of these?

No.

I plan to purchase EBL Flash-II and learn to tune it myself.

OK.

 

[L31MaxExpress]

I had none of those issues with a 25% March underdrive on the 97 van. The water pump and fan are actually 33% underdriven as well. That saves the bulk of the power. It also took a ton of stress off the ac compressor and power steering pump running the engine at higher rpm. I did remove it last year when I was having idle AC output issues with the Sanden 4261 but that turned out to be more an issue with the smaller displacement of the Sanden not the crank pulley. AC had worked great with the old 2006 era HT6 replacement Valeo compressor it previously had on it. The alternator overdrive pulley loosened up as I probably did not get it tight enough and basically friction welded itself to the old alternator and I damaged it removing it. I will put the underdrive crank pulley back on at some point when I get another overdrive pulley for the alternator.

 

[GoToGuy]

You can stuff a bunch cash into it, but the return is limited. The 305 is just lacking in potential. Some of your items the the advantage they provide in your plan is so small the cost is negative benefit.

 

[L31MaxExpress]

You can stuff a bunch cash into it, but the return is limited. The 305 is just lacking in potential. Some of your items the the advantage they provide in your plan is so small the cost is negative benefit.

I had a fairly mild 305 TBI I built make 423 hp and 418 tq. To say they are lacking in potential is not exactly true. Give the little small block some compression, head flow, cam timing, headers and a decent intake setup and it will make as much HP and TQ per cube as any other similarly modified SBC.

 

[L31MaxExpress]

For something you are just planning on messing around with the 305 can easily crank 250-275 HP and 300-330ish TQ at the crank with 081 heads and the little 1102 cam. They made 230 hp and 300 tq stock with the RPM challenged TPI, horrible factory tune, the restrictive OE log F-car manifolds and a tiny little 202/207 roller cam that only had 0.415/0.430 lift and was on a wide 117 LSA.

Years ago on a tight budget I had a 305 block built as a claimer bottom end. Flat top pistons, X rods, and some decent machine work done for a very good reasonable price. They built the short block and it was zero decked. I assembled it with a set of rebuilt 081s that had been surfaced and had a 3 angle valve job and good springs but otherwise stock. I used a replacement for the GM 929 camshaft. Same camshaft grind that came in 85% of the basic small blocks ever built including the TBI 350. I put it together with the stock TBI and TBI intake manifold and a set of 1.5" primary Flowtech long tubes into a dual 2.25 to single 3" exhaust. I had to do minimal tuning to the ECM and used 350 injectors in it. In summer heat it made 191 whp and 278 wtq on a Mustang dyno through a 700r4 and 8.5 10-bolt with a clutch fan on it. It also managed 17 mpg in mixed driving running around with the ac blasting with the 3.08 rear gear in a 5,300 lbs brick.