GM to Mopar trans swap?!

Re post 15
Maybe yes and maybe no. Could just as easily be a worn out brass ring, or insufficient clutch plate departure, or a warped/faulty clutch disc, or super thin oil.

A side cover is an A230, which is a fully synchronized 3speed.The A230s usually came with a floor-shift.
The cheapo First-Gear-Grinders were usually column shifted.

Im afraid the only sure way to know is for somebody to slide under there and look.