Motor Options

I picked up a 86 MJ 4x4 really cheap, it has the 4 cylinder 2.5 in it with a 5 speed. The motor is weak it runs but there is some blow by and such and I am wondering what is a good choice for an easy motor swap? What will bolt in with out much trouble? Thanks

Ok, I guess there was an AMC and A GM version, how do I tell which one I have for sure?

There was no GM 2.5L. The easiest upgrade would be to move up to the 4.0L inline 6. You just need to find an XJ donor and pull the engine, tranny, tcase, along with the wiring and computer. It will pretty much be a bolt in. The MJ already had dual latch hood IIRC.

What year range should I stay in? I was really hoping to keep the standard trans, but I am guessing the 6 wont bolt up to my 4 cylinder bell housing? I dont mind the 4 banger but I am guessing that is not so easy to come by.