***383 or LT, that is the question...***

okay, I've a 5.0 89 IROC as of now. I got it a K&N and stuff and it's cool and all but it's not powerful enough. Now I'm contemplating on whether I want a 383 Stroker or an LT1. Now to my knowledge 383 have the power but not much top end due to it being an old-school block. So my question is should I drop an LT1 engine in it a 383 Stroker or should I just go all original and buy another TPI engine except maybe its a 5.7L instead of a 5.0L and brim it out to the max? My fate is in your hands....

go with the 383

383 all the way. Old school would be way cheeper cus u gotta worry about harneses and computers with teh LT1!

Matt

If I were you I'd put together a nice 383 and run the stock style TPI on it (with the appropriate changes) long enough to come up with the cash for a super- or mini-ram, and then maybe drop a blower in it eventually. LT1's are great and all...and I hear the swap isn't very difficult, but the 383 will put out more power and be more fun IMHO.

WHATS WRONG WITH TPI? someone explain why TPI is considered restrictive.....

What's wrong with a 383 LT1? You think it costs much more? You could do an older LT1 intake on an "old school" block. The older block doesn't make any less power than an LT1 block.

Something simpler? Carbed LT1...make it a 383 or 396 stroker, some serious heads, big roller cam. You could make anywhere from 400Hp to 600+hp depending on how much money you wanted to spend.

Buying a crate engine from Nu-Tek, Agostino Racing Engines, MTI, or even GM is the way to go these days, especially for the guy looking for help(AKA: you:)) If I didn't already buy top end parts, i'd be buying a new Motown 415 cube crate engine from World Products:( *sniffle sniffle*

Goodluck

ps...TPI doesn't suck, only the hard intake pieces suck. The fuel delivery and other stuff is fine but the intake manifold pieces are too small for serious powermaking abilities. They are made for a 305 cubic inch engine that runs at low RPMs..i works great too with awesome torque production... Try breathing through a straw. Now run and try to do that:) Hard aye?

autoroc is right...the tpi isn't CONSIDERED restrictive on a 5.7, it IS restrictive on a 5.7. That's plain and simple fact. Don't go carb cuz fuel injection is better, IMO *I'm not looking to start a fight, so take it as nothing more than my opinion* :D . Crate engines are good, too. Actually, they cost about 1/3 to 1/2 of what buying a totally new engine from the factory (though I realize you probably wouldn't buy a brand new LT1). If I were ever to do a swap, i'd go with a good crate engine that has the things i'm looking for. Plus they should last you a while-strokers oftentimes don't, though i realize a lot of people here are having success with theirs.

Originally posted by TheGreatJ
If I were you I'd put together a nice 383 and run the stock style TPI on it (with the appropriate changes) long enough to come up with the cash for a super- or mini-ram, and then maybe drop a blower in it eventually. LT1's are great and all...and I hear the swap isn't very difficult, but the 383 will put out more power and be more fun IMHO.

I agree with this except for the stock style TPI part. Just get a Holley Stealth Ram and be done with it. That's my plan

It really depends on how much you know about computers/fuel injection and how much fuel mileage you want to save. An LS-1 will be better on gas and there isn't too much you have to do to get more horsepower. You could find a wrecked vette in a salvage yard maybe even with an LS-6 or just get the LS-6 parts to make more horsepower. I've seen the wiring harness to change it over I believe from SLP Engineering. The old-school 383' will give more torque but then you'll have to add frame connectors and you'll be stopping at every-other gas station.:cool:

I picked up a 350 block put a LPE cam,LPE L98 D port heads ported and polished, SuperRam, tes, 52mmtb and Ed Wright chip. Put those in a 87 IROC and ran 12.96 at 110 mph on the motor. Didn't have to change computers or wiring harness. AutoRoc has seen me run the times and has rode in the car. It doesn't have to be hard work to go fast.
I just picked up a NOS kit which I will install over the winter. Then we are looking at the 11. My IROC started life as a 305 TPI car.

yup, get u a nice 383 and ull be able to pass almost anything on the road except a gas station. lol

Matt

Give him a break, 383's aren't that bad on gas. I just finished mine and so far I'm getting about 10-12 mpg. The upside is that it's a blast to drive. I'm for the 383. If you want to keep the basic TPI setup, you could always go with some High Flow parts. SLP makes all kinds of stuff for them. Some High Performance parts, a little porting, and you're ready to go. That's the direction I took. Good Luck.

Either way is great. If you do go with the LT1 they run a lot more effecient due to the faster computer. That can me matched up if you run your TPI with a DFI or FAST computer.

Parts are a bit cheaper for the L98 also. A friend of mine is building a 383 LT1 and I'm building a 383 L98. Were at about the same cost so far and mine in fully forged with AFR heads. His are just ported LT1 heads and a scat crank.

Not to mention I bought everything for the motor from intake to oilpan. He bought a donnor engine and is reusing a lot of the parts.

It all really boils down to how crazy of a motor do you want to build and how much money you have. ;)

I started my project with 5g's CDN in mind. I've stopped counting at 15g's CDN. :(:(

Originally posted by StealthElephant
WHATS WRONG WITH TPI? someone explain why TPI is considered restrictive.....

Spell it out. Tuned Port as in the ports on the stock TPI are tuned for the L98 cam that came in both the L98 and LB9s. The size of the runners and the intake ports are for the rpm the L98 cam was meant to run in. Latter LT-1 and LS-1 systems are designed to flow over a broader range like the aftermarket mini-rams and others are.

it just looks so much better though.................. :(