easiest...4.0...v8 requires a lot of mods....what r u trying to build? axles? tire size?
there's more to it that just dropping a v8 in it. there is a jeep in my crew with a stock 4.0 that can do anything the v8 jeeps can do and more.
in this video the red jeep is a v8 and the black jeep in a stock 4.0. both have 2.5 ton rockwell axles and 52" tires and pto wenches
more of the stock 4.0 jeep on 53" tires And 2.5 Ton Rockwells
2003 TJ 4.0
4" Terraflex suspension lift / 2" body lift, Sway bar delete, Procomp shocks, SYE, 35" pro comp tires, Rear Locked axle, SRC side armor, SRC Rr bumper, Frt bumper/grill guard with skid plate. Airraid intake....