Will, can you post here the casting numbers for the head and block? That might help us put our collective brains to working better. A 54 block will be different than a 57 block, though because of the lower water pump on the 55-2nd and later. The head should work in any case. About 15 years ago I went the other way and put a 53 235 head on a 56-57 block. Good luck
