86 Black Roller 318, swap/interchange into 72 318

You can't use the 72 heads on the 86 block if you are using the factory style roller cam. The roller cam heads have a .660 diameter pushrod hole while the flat tappet blocks had a .500 diameter pushrod hole. The roller lifters are longer, requiring shorter pushrods which puts them at more of an angle. I think all aluminum heads have oval or the larger pushrod holes. So beware!