Yes, I’m not sure what moper is talking about, there is a “dish” on the top of an early block, but I always thought it was for clearance for the DS exhaust manifold. There is one problem, and that is if you get later smog heads with the EGR ports. The head will actually hit the DS exhaust manifold and break it if you are not careful. You can grind the head and exhaust manifold to clear. Just enough or you can break into the water jacket of the head. Had to do this on “J” heads on the 273 also.
