I'm in the process of building a 383 and im using flap top forged pistons, and the compression will be in the high 11's . So im looking to drop it a bit with a thicker gasket anyone know any part's, brand, how about fel pro, thanx

-Chris

 

AFAIK the stock GM one is the thickest one out there.

 

I believe it's from largest to smallest: GM, Fel-Pro, ImpalaSS

 

Cometic makes custom thickness head gaskets. I had to order a set of .057" gaskets for our 386 in our race car, because I had .022" POSITIVE deck clearance. Cometic gaskets are also reuseable. The machine shop I deal with have been replacing conventional wire ring arrangements on forced induction cars with regular Cometics, and have had excellent results. They are a little pricey. We paid $140 for the set for the 386.

Frank

 

than for the info, i think i heard before that the impala ss gasket is thiner or im i rwrong?

thanx

 

Yes, its thinner.

 

I'm running a felpro 1074 (.039) on flat-tops in a 383 with a +.002 deck. It works out to be right at 12.45ish on compression, and I have no troubles. Just set your up for mid to high 11's on the compression, and tune it into submission Makes for a fun and snappy combination on the street IMHO. (and yes, I run it on local crappy pump gas - 91 to 93 oct). Don't be afraid of compression on these motors man. The computer is an awsome advantage when done setup correctly.

Dave C.

 

Just wanted to add this. While I was building the 386, the heads were torqued down, and then removed twice before it ever left the engine stand...With the same Cometic gaskets. The car now has over 40 runs on it, and runs 10.90's. I'll never use anything but Cometic in anything else I build.
http://www.cometic.com/

Frank

 

I am not sure which ones TPIS sells but I know they offer a thicker head gasket for LT1's. Call em up.

-Dustin-

 

Well i got some forged flat tops too for this 383 im building, so if id ont use a thicker head gasket i'll br around 11.5 compression and it's going to be a daily driver and im going to spray thats' fine lol?

haha thanx

and if i want to drop it to say 11:1 what size gasket do i need lol

thanx

 

pretty sure it's:

GM stocker @ .051

Fel-pro 1074 @ .039

GM Impy @ .021

pick your poison..

Somebody correct me on these if I missed the numbers..

Dave C.

 

As far as I know (which may be incorrect)
GM stocker @ .049

Fel-pro 1074 @ .039

GM Impy @ .029

Mr Gasket 5716 @ .026

 

That's what I've always heard.

 

So let me get this right, the fel-pro and mr gasket you guys posted are thicker then stock? Anyone know stock size for sure?

thanx guys

-chris

 

No they are thinner. Hence the numbers being smaller.