Is there a difference in cylinder deck height on Oldsmobile 371 and 394 engines?

It depends on the 371 your talking about the 57-58 371 is a raised deck height from the 54-56 324 engine. Then in 1959 they raised the deck height again so the 59-64 engines use the same deck height, which means the 59-60 371 engines being the last 371's share the same deck height as the 394 engines. Hope this helps you out.