Yeah man, bigger valves, same head bolt spacing, same valve/rocker geometry. I think pushrods are different length, only by like .020" or so, I can double check. I know the 6.4's have a higher valve height, 6.0's are like 2.220, I think 6.4's are like 2.300. That could be fixed with the right length pushrods, and or rockers from the right engine, or even Elite diesels adjustable rocker arms...although that ads another 3 grand to the cost. For the trouble, probably better off just swapping an entire 6.4...but honestly, I'd take a 6.0 over the 6.4, except for the fuel system. 6.4 blocks have way thinner castings, and for some reason wear out the valves more it seems like.Gearhead you took my ideas right out of my head. What are you psychic? Lol I have been trying to figure a way to convert a 6.0 to a smaller dispacement 6.4 or at least the commonrail fuel setup and maybe even the turbo's. I agree it would definitely be a MAJOR undertaking but I think that if someone gets it right it would be one seriously BAD A$$ 6.0 with limitless options.