So im really confused here on what to do. I have never looked into quench before until today. I have a stock decked block. i want to run fel pro 1094 on my motor to give me a 0.040 quench but i have aluminum heads and a undecked block.. so what do i do. here are my specs. i dont want to deck the block. if i run a composition gasket it will be around .065 quench is that bad or do able?

.025 piston in the bore.
2 valve flat tops 3.4cc forged.
64cc new aluminum heads.

so what do i do? run the high quench or use the steel shim if i even can?

 

You probably saw somewhere, "Don't use steel shim head gaskets with aluminum heads!" Well, Fel-Pro doesn't seem to agree:

http://www.felpro-only.com/break_roo...heads#pid22524

See threads 3 & 4.

I would say since your deck hasn't been milled to clean it up, put a light coat of Copper Coat on them and go.

Note the 1094s no longer have the Viton rubber coating on them, but a clear silicone coating. An improvement, I would say.

 

Unless the decks are warped out of spec, don't have them cut.
Then what, you lose block strength and then try to replace that with a thicker gasket?
Not the smart thing to do. Just run the thinner head gasket.
It ends up the same, and you will not have to machine the intake manifold to fit, because you cut the decks and screwed up the geometry.

 

thanks for the reply guys im using a 1094 coating bith sides ill let you know how it goes.

 

Gm performance gasket .028" thick. Use that for a .053 quench. Works good

 

I have used the 1094 gasket with alum heads on a non decked engine many times and never had an issue.