86 Black Roller 318, swap/interchange into 72 318

AJ/FormS said

Seriously, indeed you are a
FunnyOldMan.

There doesn't seem to any rhyme nor reason to your plan.
Or if there is, I'm too dense to see it.

Click to expand...

Plan is to have a spare short block, swap heads and aim to have 400 fwhp down the line from one of the 2. Needed to know what would interchange to keep, remove to sell, and what to toss.