The KB hypereutectics are very close to zero deck, just be careful of the intake valve eyebrows are so big they dont leave much meat around the bores, at least on a standard 3.91 bore, an oversize is probably fine.

I built a 341" motor with those KB's in a standard bore low mileage 318 block and a 3.55 stroke MP crank with 6" aluminum rods, it rev'ed like a Banshee