Tech
the head casting # is 14102193, They are a center bolt valve cover style head. they are unmodified NOS heads, they have a large combustion chamber but I don't have any way to measure them right now.
I was thinking about using these...
http://www.amazon.com/Chevy-Flat-Pis.../dp/B00D9T5Q2G
I know Amazon is probably not the best place to buy pistons but the price seems pretty good.
I will look into the late model block with adapter, it would be nice to use the stock roller cam parts instead of retro fit kits.
Casey