ok so this is my first post so ill try to sound as un-newbie-ish as possible. Im pretty new to engines and all (only 18), but im looking to build a 383 for my truck (94 Z71 ex cab 4x4 etc etc, its lifted and will soon be lifted more). I know its not a 3rd gen, but this seems to be the best source for info on engine building. What intake/injection system would ya'll recommend for my application. Obviously right now its just a stock 350 TBI, but ill be starting from scratch with a different block and going from there. A friend has a TBI 383 thats running about 350hp/450 ft lbs and getting about 14mpg in an 88 4x4 suburban, so i am basing this build up off of that motor. However, a lot of people have recommended going to TPI as it is a more efficient system. I came here to read up on it, but then came across about 10 other setups that could be run, and now im lost. Should i stick to TBI, upgrade to TPI? or if there an even better route for me? Right now i have a lead on a complete 305 TPI from an 87 IROC for $390 obo, i could buy it, steal the TPI stuff and part out the rest, then mod whatever parts would be necessary to feed the 383. Or i could go a completely different route if ya'll think it would be more effective for my purpose. This is a big lifted truck i know its not a speed demon, but the more power i can work out the better, expecially torque of course.

 

if you change from tbi you'll need to change the harness and ecm to go with any other efi system. i doubt you'll pass e check with anything but tbi.

 

I beg to differ. The TBI system is a continuous spray wheras TPI only sprays for every ignition event. So not as much fuel is sprated. Now with all of the aftermarket ECMs we are able to control whether it is batch or bank fire. We can turn the fuel pressure down till it barely runs, make the pulse width tiny and turn enrichment waaaay down. Bank fire will spray even less fuel compared with batch fire and then to TBI. This is of course assuming that injectors are not huge and fuel pressue is at a OK level. RS' also only came with one cat. TPI cars camee with two cats. So put on two cats for TPI. I have heard the "You won't pass emissions" if you do____, argument alot. But consider this: I have very many friends that have done MILD performance rebuilds and have seen an increase in gas mileage. This was all done with bigger cams, injectors, and bumped up fuel pressure, etc,. As long as you stay within the "Sensible"limit on performance and emissions, you should be fine. It should also be noted that some states do not do anything to your car, some only check to see if the safety features work and some do not look under your hood. There are also the tried cheating techniques of using a bottle of rubbing alcohol or the octane booster. Search for some of the posts pertaining to emissions.

 

Cali has a visual inspection. Meaning, the guy looks to make sure that any mods that have been done are accompanied by a CARB sticker.
And they recheck every 2 yrs. It makes it tough.

NorcalZ71... Is your truck going to be street legal? Have you checked into your local smog laws?
Cause unless your name is Schwartznegger, you gotta play by the same rules as everyone else.
I have a truck that I'm modding. I'm not done yet, but I've done some homework, and I could give you some ideas.
The big Q is... is it gonna be smog legal. Cause it puts some major limitations on your project if it's going to be. There is good news tho... Most aftermarket truck stuff is 50 state legal anyhow.

If you want to, PM me and I'll compare notes with you.

 

kalifornia has visual if it came with tbi i think you're limited to tbi

 

You can change induction systems, but only if the entire matching engine, ECM, and tranny from a later model are swapped.
An LT1 engine & trans would be legal.
But a TPI is out cause they stopped making em by '94.
The Edelbrock MPFI is a good 50 state mod tho. And guys have put stroker cranks in, and still passed smog.