That much modification is going to require a couple of extra precautions- - - - -Grade 8 studs, not bolts, to hold the head on, and a solid copper head gasket. Find someone with a plasma cutter or a water jet, and use the original head gasket as a template to cut out about six layers of .040" or maybe .060" sheet copper. The machine setup time will be the same as making only one. and you'll have a supply of replacements. That's what we did on the blower equipped "426" hemi we ran on the truck pull circuit (which was actually 547 cubic inches).
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!