Got a early 70's pontiac 400. THe heads are the 6X I think,ny cousin tried to "build " something out of it.....It is a 4 bolt block ( the first one i'v ran across) but it has a 455 h.o crank and caps on it . Would need to get right crank&caps. Up fer offers. this would be a killer pontiac motor if redone right......Open to offers/trades.