I know the distributor swap goes backwards with some modification so the older engines can have HEI ( electronic ignition ), I guess you could go forward as well and keep the older distributor for a newer engine.

http://chevellestuff.net/qd/engine_stamp_numbers.htm
http://www.nastyz28.com/chevy-engine-code-stampings.php

These two links are mostly about the small and big blocks, but the same numbering system works on the inlines.

1937 Chevrolet Inline-powered Streetrod