big block early a roll call?

Mine is a factory 3 on the tree. But the more I look at it, the more I can see my 383 sittin in it. Do you happen to know which HP manifolds will fit the easiest? I've read that they will fit. The passenger side supposedly falls in and the driver's side just needs a double u joint in the steering shaft. But I don't know which ones. I was thinkin maybe B body?