Originally Posted by JurassicJeeper93
Just got my 06 tj! Love it but the 2.5l isn't for me. I'm hoping to put a 4.0l in soon, I was wondering if I go bigger with the engine is there anything else I should upgrade as well?
to swap in the 4.0, you will need not only the engine, but the transmission, transfercase, and computer(and maybe the wire harness to IIRC) from the jeep it came out of. you will need to cut off the original engine mounts and weld on new ones in the correct place. lots of work, and lots of parts. this is why so many times it is suggested to just go up to a V8, as you would be doing all that anyways. depending on your desired tire size, and new rear axle as well if going to the 4.0, and if a v8 is desired, a stronger rear end will pretty much be required.