Liquidsteel

Story short, this engine was in my camaro with TBI ran like a champ. I bought a 1991 Firebird, with a 350 tpi engine in it, had SLP package set.

I've read accrossed the board, that TPI is to restricted for a 383, i wanted to know if the Holley Stealth ram intake/plenum. Would solve this problem or is there another route to go, other than Carb

Orr89RocZ

iTrader: (20)

Whats the engine combo your thinking of? What is your power goals with this thing? Do you want to rev over 4500 rpm?

Stealth ram should support all you want out of a streetable TPI. Capable of pulling to over 6000 rpm and making 400whp for sure. Depends on the cam/heads/compression tho, but Stealth ram is abit better than TPI intakes if your looking for good power over 4500. A 383 does like airflow so at the very least, a fully ported TPI base with some big runners or SLP siamesed/ported out runners would be minimum i think. I do know the vortec tpi base is limited in how much material you can port. There are guys getting regular TPI aftermarket bases to 250-260 cfm easy and up around 280-300 with cut/reweld the ports. I think the vortecs need extreme mods to reach that air flow.

Stealth ram is suppose to flow 265-275 out the box, but not sure what the vortec version can do. Either way thats plenty for vortec heads

Liquidsteel

350 bored .60, Flat top,11.1 compression pistons, cam is XR276HR, 1.6 rollers Rockers. Everything is forged

Honestly i wanted atleast 400hp if possible and be able to turn up to atleast 6,000 rpm, I doubt the cam make power up to that point. Pretty much street/strip. I have a dialy driver. Trying to keep those imports in there place where i live.

Orr89RocZ

iTrader: (20)

Do the stealth ram then for sure on that setup.

Problem is, 11 to 1 compression is way to high for iron vortecs. Are you running an aluminum vortec style head like an E-tec or Fastburn?

If thats the case, then you can easily go 1 step up on the cam and easily make over 400hp on motor.. somewhere in the mid high 300's at the tires which is good for possible high 11's in the 1/4

Liquidsteel

Yeah there IRON , had them machine for 2.02, 1.6 that may hurt me also.

1989GTATransAm

iTrader: (3)

"350 bored .60,"

Danger! Will Robinson.

Liquidsteel

Why you say that? I sold my other engine is .60 over, 4 years old and going?

Orr89RocZ

iTrader: (20)

I believe he means .60 would make it a 4.6" bore, and you mean to say .060"

Anyway, larger valves arent necessarily a bad thing, you just have way too much compression to run on pump gas. Need to drop down to mid high 9's to be comfortable. 10.0 is max i'd do with pump gas and iron heads

Liquidsteel

What problem would develope from running 93?

Orr89RocZ

iTrader: (20)

It more than likely will ping like crazy at 11 to 1 compression with 93 octane gas. Combustion temps will be very high. Only ways to combat that is to go with a big cam to bleed off dynamic compression and colder plugs and pull timing. That wont be a cure for all of it tho, and is an inefficient way of doing things. Other option is to run higher octane race gas.

best options are change pistons or go to an aluminum head, or if they make a large chamber iron vortec head, that would work to get compression down.