What head gaskets are best for a 5.0L ford with aluminum heads and running 16 to 18 psig boost? Mayf, providing head & deck surfaces are flat and are torqued correctly, the Cometics will be fine. Even the good old blue Teflon coated Fel-Pros can perform surprisingly well. You 'rattle em'.............."you'll lose em, however. Chris H.........NZed.