V8 (5.2) swapping a van
The best options are the ones that are the most economically infeasible. Cummins intercooled 4BT. 30mpg and decent power. finding a place to stuff the intercooler in may somewhat "difficult", though. But if "I" were doing it, 5.7 Gen III all the way. That'd be fun one! Well, except for that whole installation thing!
:rofl: