I'm in the "drawing board" stages of putting a 4.2 DOHC cylinder head on a 261 stovebolt block. The problem you're going to encounter with running the complete engine is all the computer controls involved. I've also investigated the possibility of turning the 4.2 into a "dumb" engine with a carburetor, a distributor, and fixed exhaust cam timing. I think both ideas are worth some more attention. That oddball oil pan with the axle shaft tunnel through it would also have to be modified for front axle clearance.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!