You are prodding my memory banks. Friend of mine, long ago, picked up a diesel Chevrolet G-van with a blown engine, cheap. (6.2 non turbo diesel). What was in the van was a non lockup TH350 without overdrive, which was not the original transmission for the application, it should have been an overdrive 700R4. Problem there is that you have a crankshaft 3 inches diameter on the input side of a torque converter, the other side of which (trans input shaft) is maybe 1 inch diameter ...
He deduced that the 700R4 (which has a mechanical load sensing cable) blew up, and the original owner dropped in a TH350 (which has a vac modulator) but without anywhere to hook the vac modulator up to, they just left it unconnected ... so the trans would simply always shift at max revs ... and that led to the 6.2 blowing up ... and that led to the frustrated owner selling off the remains cheap.
With a replacement engine and a built 700R4, it was fine ... well, as fine as a GM G-van with a non-turbo 6.2 will be ...