The strongest gaskets are the steel ones. As the gasket gets thicker, it seals oil better and compression less well (weaker). That said:
1. Strongest: steel, .018"-.020" thick.
2. Next: FoMoCo "C" series composites, .027" thick.
3. Next: Victor brand, about .040"-.045" thick.
4. Next: Fel-Pro brand, about .050"-.055" thick.
5. Last: FoMoCo "H" series gasket, .080" thick.
I have one of the "C" series FoMoCo units left. PM me if your interested: James bought the other one for his Falcon.
Obviously, the compression ratio should have some bearing on your decision, as the difference between the thickest one above and the thinnest one will change the compression ratio by about 2 numbers.
