I think where the confusion has arisen is from my dad understanding that the engine builder said the KB160 pistons were made specifically for a close chamber head. I don't believe thats a good fact. Thats alot of dome to get into a small chamber isn't it? Course I'm a sb man so I haven't had the chance to check out too many bbc heads yet.I guess the 781 heads will work just fine. While I have you here whats the scoop on the 049 heads? Thanks guys.