That's why I was thinking maybe a (RWD) Lambda motor from Kia/Hyundai might be a candidate, as well as a bunch of Chrysler motors.

I know that the Chrysler (non-Mitsu) 3.3 and 3.8 will mount to a Mitsu 6G7 bell housing, they were selling Voyager minivans with both motors on the same transmission for a while and I read a write-up a few years ago about a guy who put a 3.8 Chrysler on his 5-speed Mitsu 3.0 equipped minivan (sorry I don't have a link anymore)

So if the 3.3 and 3.8 Chrysler interchange with the 3.0 Mitsu, and the 3.0 interchanges with the 3.5 Mitsu, that opens you up to digging 3.8's out of minivans and Wranglers through 2011... and maybe 3.6 pentastars? That's a rev happy, variable valve timing motor with a pile of torque, like 250 lbs at 1500rpm..