Block can be one of these; C6AE-C, C8OE-A, C8TE-B, plus the mexican block (don't have the numbers for that one) Heads can be C8OE-F, J, K, L, M. C8AE-J,C8DE-F. Intake would be C8ZE for the 4 bbl. I don't know what the 2 bbl was. As for everything else, good luck ! Any 302 part with a 68 date code would probably be correct.