[Mike C]

Hey JimmyBum, I'm doing the same thing. I've got a set of 290 heads and a 512 block. Both from a '69 427. The heads are most likely 101cc, but please post casting number. Maybe a call to Scoggin Dickey is in order, I have heard good things about the Mark VI Vortec heads. They are 99cc and are said to fit mark IV blocks with the right gasket. Flow way better than the old school heads, and are not much more expensive than completely R&Ring your originals. This is most likely the way I will go if all sorts out. Compression with a TRW flat top should be about 9.5;1, that's what I'm shooting for.