Are you wanting to put a 272 oil pump with a 272(+) distributor in a 256 engine block?
I've been told there are two different versions of the '54 256 engine, 'early' & 'late'. The early ones use a smaller camshaft with a different size distributor drive gear, like the 239 engines. The later version uses the; larger camshaft, distributor, oil pump parts that are compatible with the 272 thru 312 pieces. Count the teeth, 13 or 14, not interchangeable.