But plan B sounds doable and hopefully only mildly complicated. Gotta love Mopar the interchangeability of the era.
I'm glad you don't stay down for long
Yanking an engine and transmission entails more brute force than complexity as far as obstacles go. Think: 620 + 160 lbs = 780 lbs. While I have a hoist, sundry jacks and stuff, that still is a lot of dead weight for one old junky to maneuver. I recall the fun I had with the 400 and its associated 727 4 yrs ago. Still, I have plenty tools and know Archimedes Principle, so, with God's help, I should be able to swing the drive plant out of Mathilda's wreck and into Gertrude without too much pain or drama. Hooking the motr back up after mounting it will be no more difficult than it was for that damned gasket and block cleaning job a few weeks ago, and I will be delighted to put some of those parts BACK on the GOOD motor.
If/when I get an opportunity, I want to disassemble Gertrude's engine down to the bare block. I expect to find a crack in one of the 2 rear passenger side cylinder bores after cleaning things out. THAT would explain the accumulated crap in the coolant jacket AND the futility of the head gasket and block cleansing job.
But I'm in no hurry to do that autopsy. That engine won't move a shopping cart until serious effort is put into it, and I have better blocks for such effort. We're going to build that 400, though I want a forged crank from one of the spare 383s, if naught is amiss with them.
Wish us well for these plans. FIRST,I need to get Gertrude moving RELIABLY! Deo volente.....