I am building a 440 using Stealth aluminum heads and 9.35:1 compression and a Summit 6401 cam. I have run the combination by all the manufacturers involved and many here and no-one has said I can't do it (though my combination isn't optimum, long story). As far as gaskets go, some have run .020" steel shim gaskets with aluminum heads successfully by coating them, though 440 Source warned against it. I am using .027" Cometic multi-layer stainless gaskets that are ok for aluminum.