are there any .020 gaskets that will hold up raw water marine use in a gen 5 or 6 engine? or do i stop trying to chase that half a point the cheap way?

cometic can make you some.

I'm going to be running some cometic .027s. They are MLS, stainless shim steel. If you go to .020 just make sure heads and decks are straight and piston to head clearance is enough (.035ish minimum)

for a half a point in compression why would you spend a chunk of chanage for a cometic mls gasket to gain nothing in speed?also if your head&deck surface is not properly prepped the mls gasket won,t seal.

I have a bad habit of asking questions the answers can be found elsewhere for. ,2 GM gaskets. 14097000 .027 composite. 12555728 steel .022. I assume steel shim, not mls. For 4.25 bore gen 5-6 engines. Both in the 27-28 buck range.

A different way to ask what others already did.

How far in the hole is your piston?

Be careful trying to gain compression with a thin gasket. Keep in mind piston rock when measuring how far in the hole your piston is.

I guess i should measure instead of assuming 020