Just spoke with my buddies again and they needed ‘just’ a drivetrain choice as they already have a car in mind.

They would love a 4 banger, but would work with a 6 cylinder. They are trying to keep it a simple swap as they have limited room to work with and don’t want over complicated engine electronics. Thanks for the help soo far. If they decide on a jeep 4.0, do you think it would work?