Why everyone carb swapping?

[oefvet0708]

To the op, I am building a 355 l31 going with brodix 200 ix heads, mild comp cam, full roller valve train, 10.5:1 compression with .25 quench, and upgrading the intake manifold. There is basically a knock off of the edelbrock pro Flo manifold for a couple hundred bucks that comes with basically everything you need except the injectors. This will basically convert the l31 to a tpi-ish true mpfi manifold that can use you stock throttle body. The only thing you to do is:

-source good quality injectors with size determined by power levels
-external efi fuel pressure regulator
-some an fittings to use the factory fuel supply lines
-either a. Separate out the injector harness for each individual injector which is more cost effective but can be tedious or b. Buy a tpi injector harness of scoggin-dickey that will look factory fit and finish and buy the injector plug for the pcm side of the injector harness and re-pin that but this route is a little more pricey.

But at that point there is no tuning required unless doing other engine mods but a decent tune is never without its benefits

 

[Scooterwrench]

To the op, I am building a 355 l31 going with brodix 200 ix heads, mild comp cam, full roller valve train, 10.5:1 compression with .25 quench, and upgrading the intake manifold. There is basically a knock off of the edelbrock pro Flo manifold for a couple hundred bucks that comes with basically everything you need except the injectors. This will basically convert the l31 to a tpi-ish true mpfi manifold that can use you stock throttle body. The only thing you to do is:

-source good quality injectors with size determined by power levels
-external efi fuel pressure regulator
-some an fittings to use the factory fuel supply lines
-either a. Separate out the injector harness for each individual injector which is more cost effective but can be tedious or b. Buy a tpi injector harness of scoggin-dickey that will look factory fit and finish and buy the injector plug for the pcm side of the injector harness and re-pin that but this route is a little more pricey.

But at that point there is no tuning required unless doing other engine mods but a decent tune is never without its benefits

Factory or Edelbrock PCM? MaxEx just went through some hair pulling with his ProFlow. Not sure he's tossed it in the trash yet but it was going that way. Wish you luck with "no tuning required"

 

[Cadillacmak]

Follow your gut.

I hopped in the 75 f250 last night to run to the store and I was thinking on the way how nice old school is to just drive! It could be tuned better I am sure, but when I stomp on the throttle it just takes off and makes me smile! Its not factory, Shelby intake, long tube headers, HEI, etc, but all old school mods. Sometimes you just need fun, not perfect.

 

[Scooterwrench]

I hopped in the 75 f250 last night to run to the store and I was thinking on the way how nice old school is to just drive! It could be tuned better I am sure, but when I stomp on the throttle it just takes off and makes me smile! Its not factory, Shelby intake, long tube headers, HEI, etc, but all old school mods. Sometimes you just need fun, not perfect.

Yeah, we get too OCD with these things chasing that perfection. I've gotten better at saying "that's good enough"! It's not a perfect world, deal with it!

 

[RichLo]

I hopped in the 75 f250 last night to run to the store and I was thinking on the way how nice old school is to just drive! It could be tuned better I am sure, but when I stomp on the throttle it just takes off and makes me smile! Its not factory, Shelby intake, long tube headers, HEI, etc, but all old school mods. Sometimes you just need fun, not perfect.

Perfect way of putting it! There's a time and place for reliable fuel injection... 5am going to work with a coffee in hand still half asleep.

Then when you want nostalgia, jump in a classic after work or on the weekend and have fun.

I wouldn't mix the two with a 'resto-mod' LS swapped classic, it brings the fun out of driving it. You know, sitting at a stop light with the whole car shaking then you feel the slightest stumble and your heart skips a beat so you gas it a tad just to bring it off-idle in case it wants to stall then the light turns green and you feel the whole car twist and you get a faint aroma of unburnt 91 with lead additive. Every time a classic makes it to a destination without any troubles, it feels like a miracle.

 

[oefvet0708]

Factory or Edelbrock PCM? MaxEx just went through some hair pulling with his ProFlow. Not sure he's tossed it in the trash yet but it was going that way. Wish you luck with "no tuning required"

Right. Not actual edelbrock pro-Flo just the manifold. Good ol Chinese knock off manifold. I am pretty sure that if you run the same size 24 lb injectors that came stock on the vortec other then running dedicated injector harnesses, the pcm will not to be tuned for said injectors and voila you have actual mpfi my guy.

No reason for all the sarcasm. I love how all the “old timers” that have been on these forums since inception thinks that they’re word is gold and everybody else is inferior. Some are here to learn and some of us are here to help. which one are you? I was just giving an alternative to the junk spider injection system on these trucks.

 

[Cadillacmak]

Perfect way of putting it! There's a time and place for reliable fuel injection... 5am going to work with a coffee in hand still half asleep.

Then when you want nostalgia, jump in a classic after work or on the weekend and have fun.

I run an electrical construction company (I am not the owner) out of an office in my house so I just have fun classics and the wife gets the reliable OBS, and her Vette.

 

[Hipster]

No reason for all the sarcasm. I love how all the “old timers” that have been on these forums since inception thinks that they’re word is gold and everybody else is inferior. Some are here to learn and some of us are here to help. which one are you? I was just giving an alternative to the junk spider injection system on these trucks.

I'm not getting sarcasm. 10.5 cr., undisclosed cam, improved headflow, and it's not hard to conclude a stock tune is going to be problematic. You're way past stock. If your quench is actually .25 that's a quarter inch. If you meant .025 that's too close. A spun bearing can crash a piston into the head. We all make mistakes time to time. You might want to double check and post accurate info if trying to help.

At this point you're in "I hope this works" phase. That is the extent of your expertise.

Watched many a guy overbuild for the intended use and turn one into a hot engine, deep geared, loose converter, temperamental disasters that no longer are any fun to drive more than a 1/4 mile at a time. You wouldn't be the first guy that's posted up here that thought he could bypass the tuning and destroyed a brand new engine by doing so. Most "Old Timers" biggest issues revolve around triggered cancel culture, delicate, snowflakes that have themselves bs'd into believing their geniuses.

 

[SAATR]

I've never really agreed with the disgust that seems to surround the factory Vortec injection system. In my personal and professional experience with them, they perform their intended function fairly well. When diagnosing customer complaints and problems with my personal vehicles, I've never actually had an issue with the spider. Plenty of LIM gaskets, distributor caps, and wiring issues, but never a problem traced back to the injectors. I understand that they are far, far from ideal for a performance engine, but completely adequate for their intended role. In fact, I feel like the system may have been intentionally designed to make modifications difficult and, in effect, nerf the engine's power potential to make the then-coming LS powered trucks seem that much better. But, conspiracy theories aside, the system just works. And considering how many tens or hundreds of thousands of these trucks that are still on the road, likely with the bulk of their factory parts in place, I would say GM did just fine.