head gaskets

True story on the MLS gaskets...installing them on an improperly prepped, or slightly warped surface won't allow proper sealing because they don't conform to imperfections like composite gaskets such as FP permatorques...at least that's my experience with them. But, if your surfaces are properly prepped they're great gaskets and seal up pretty well under boost or nitrous.

Locomotion is correct about the dead space perspective, but for a mild street build, neither you nor the engine will likely know a difference.

permatorque gaskets worked perfectly fine in my blown 5.0 Mustang...2+ years daily driving and "spirited driving" under 10-12 psi (depending on the density altitude).