[rotorwrench]

You can swap heads but holes have to be plugged to do it. I seem to remember seeing at least one 8BA that was modified to use the 59A pan by cutting one of the cast iron truck half bells and modifying the bell to bolt to the pan. Folks have been playing with these old motors so long there probably hasn't been too many things that haven't been tried. Now whether many of these mods worked or not is something else. If the cylinders are damaged on the 59A where they can still be sleeved, you might condider that. If the pan rails are still good, it won't break the bank to get a couple of sleeves installed.

The only other thing to be warry of is using 59A crank with 8BA rods. The older cranks are missing an oil hole on each con rod journal so that won't work. You can use near all the old stuff in the later 8BA engines for conversion purposes as long as it will get lubed like it was designed too.