Don't start it till you the very least get some custom cut domes for it. (Call Titan Racing) Or send the whole thing to a builder who has worked with the Power Valve motors. Ignore the existence of Trinity in this universe.....you weren't personally violated at this point, so don't give them the chance.
Sorry,my bad. Too many destroyed 72mm and 73.5 mm pistons over the years to remember that my original "400 Cheetah" had the smaller pistons.
Whatever head he uses.........the domes better not be from Trinity.
Besides, if all he has is a crank and a head shell......he should really think hard about that motor choice.