I have an 88 GTA with the 350 TPI. My motor has 116K on it and it's in need of a rebuild. I was looking at rebuilding it to a 383, but it sounds like more of a hassle than I want to deal with. I'd rather just buy the short block and swap it out. Anybody have any recommendations on what I should look for? I'd like to get my car up around 400 HP eventually, but I just want to get the 383 block in there. From what I've read, I could put the 383 short block in there and put all my TPI stuff and heads back on for the time being right? I'll eventually get new heads and headers and a few other things. Thanks for any info! Matt

 

You can put all your TPI stuff on a 383. It'll kill that poor engine, though.

Major TPI mods are required to support a 383. About all you'll have left are a ported plenum, fuel rails, harness, etc. The base, runners, TB, injectors, non-adjustable regulator have to go (you might be able to get by with a ported base). Getting 400 hp is still going to be difficult, though. SDPC got all of 358 HP out of a Vortec-headed-based TPI engine with their Vortec base, Edelbrock runners, 58mm TB, and 1-3/4" headers - to say nothing of Hot Cam and 1.6 rockers. The extra 33 CI is going to give you about 34 extra ponies - ~390 HP, all else being equal. Assuming the TPI can handle the extra flow from the extra cubes, which might be assuming a lot.

 

ok what about a 383 block with the l98 heads? and a stealth ram and all the stuff needed for that?

Anyone done that? I'm thinking of doing that if i can.

 

according to october2002 carcraft a .030 350 with a lunati hydraulic cam 225/235 @.050 lift 112 lobeseparation and .477/.507 lift with holley cylender heads and holley stealth ram efi they got 425 lb-ft @4600 rpm and 405 hp @5500 rpm. o yah and the torque curve was very flt, had 400lb-ft at 2800 and still had 400lb-ft @5400 rpm. so with a 383 version you can expect about 30 more hp and 30 more lb-ft of torque

 

sorry i forgot you were going to use teh l98 heads. my guess is that you would have about the same 405 hp as the 355 but keep all the low end torque of the 383 with teh l98 heads vs teh holley heads