daily driver on its last leg

That 2.6L engine is an interference engine with a balance shaft. They are not exactly cheap to overhaul, but if you don't let the timing belt break it is not too bad. The transmission is usually ok if the oil has been changed occasionally.

But you want to know about swaps. I have done a lot of swaps over the past 4 decades, some good & some stupid along the way. Before there was an internet there was no way to look and see if anybody else had tried the same thing...

A 350 chebby has been put in those trucks before. Since the LA mopar has similar properties it probably can be crammed in there as well. After a lot of swaps I have learned to look for which end of the engine the sump/distributor are on as the biggest clue. In the case of the isuzu pickup / 350 - a stock pan fits & the GM distributor clears.

http://www.cardomain.com/ride/426188/1992-isuzu-regular-cab

That guy used the GM iron manifolds that went above the plugs, we have similar manifolds available. He used the TH350, so a torqueflite will fit.

Good luck with your project.

B.