If you are designing heads from scratch, why would you need "blueprints" of existing heads? You need the c-c bore spacing (common knowledge), the x-y locations of the head bolts relative to the bores, the x-y locations for the pushrods, and the location of the coolant passages (buy a head gasket ). The combustion chamber volume is defined by the current head... use 54cc. Beyond that, what do you need? If you are capable of designing and building hemispherical heads, you should be able to figure out the "givens".