my honest opinion is keep it light keep it a 4 banger.. Not only will the tranny and t case or cases hold up but will the axles hold up? Any one I know running a v8 and toy axles has problems blowing up ring and pinions expecially if they arent stock gears... But also depends on how you wheel aswell.
If you ditch the turbo sell it and just buy a re for what you sell the ret for