dizwiz24

Ive got the heads off my motor and am going to be putting new head gaskets on.

The heads are new (perfect mounting surface) and the motor deck will be scrape'd with a razor blade scraper.

Whats your favorite head gasket?

A long-term guy I know swears by the OEM GM head gasket. He claims the block surface needs to be 'cleaned up' before you can use Fel-pro 1074's or any aftermarket gasket.

He claims the gm head gasket is best in my case (w/ a motor deck that is been only scrape'd vs. machined).

This car will put down about 525 rwhp/ 500 rwtq.

onefastmx5

Cant say what, the"best" gasket is for an lt1, as I'm currently doing one of these for my first time (using a cometic). However, I can tell you prep is very important. I always used razor blade and contact cleaner to clean and scuff. The last thing u want is a ultra smooth finish, but be careful not to score or scratch the mating surfaces. Proper head bolt torque is crucial as well. I'm sure others can give finer details

dizwiz24

Ok. The cometic is what I was specifically warned about. Something about the deck and head needed machined specially for the cometic...


I don't know any more than that.

onefastmx5

I'll have to look into that, haven't heard that before. But the block is getting decked and heads milled.

DirtyDaveW

I, too, have read on several posts that the surfaces of the heads AND the block need to be pristine to assure a good seal. I've used the tried and true Fel Pro 1074 for both nitrous and Turbo and they've always sealed well. I 'was' able to push water at PSI's above 11 psi but I felt that was the relatively thin decks of the stock ported LT1 heads that were the cause of that. I may be wrong but that was the reason I went to thicker decked heads. Since the swap(and another pair of 1074's) I haven't pushed water even at 18psi.
I had inquired about the viability of the Impala SS stainless steel shim (.029 compressed height) for forced induction purposes but never got a response.

The 1074 compressed height is .039

Mike Mikerson

From Cometics Web Site. they need a certain micro finish. Do Not use them unless you have the head and block prepped accordingly.

Cometic Gasket, Inc.