Other Mitsu engines for 1st gen D-50

Has anyone done or considered swapping a 3.5 dohc from a montero or a front drive mopar? Onto an auto should work since they are all auto trans apps, or am I missing something? How about the other smaller v6s like the 2.5, 2.7, 3.2 ? I'm curious since these are plentiful in Pittsburgh yards, and a lot more power than the stock 2.6.