All of my distributors appear to mount the exact same way as each
That's what my 1980 GM HEI ignition distributors looks like, and mounts
That's what my 79 Opus (box on the side) distributor looks like and
mounts like, as well all the various other earlier engine and their
distributors. Rimmers is showing it as unchanged for all years except
the GM HEI 1500.
I've never bothered to swap things around, but it appears they are all
the same, or at least compatible.
That's the funny little pedestal that mounts to the block. The part
shows as unchanged for all years of production.