Disappointed to report the following
I put an HEI distributor in my Mach 1
To fit it, I had to use an offset baseplate with a 14" air cleaner. Even this required a bit of massaging with a ball peen hammer
but it came out just fine.
Due to the interference between the air cleaner and the distributor, the relocated air cleaner is now 1 1/2 inches farther back than the normal position and there is no way I can fit a ram air set up without making a custom plenum and it really just isn't worth it.
I still would live to have the vacuum operated flappers ducting fresh air into the engine compartment, but don't want to have them letting water run in to just get everywhere.
Looks like I am not going to get what I want this time.