I acquired an LS1 for my '01 TJ.
I figured the engine would be the last thing I got for this project, but it fell into place nicely and I was able to pick one up. I had initially planned on going w/ a 5.3L, but my buddy is a mechanic at a GM dealership and came across an LS1 out of an '04 Corvette w/ 40k miles on the clock. Engine has a blown head gasket and the guy wanted a brand new engine. Works for me... I was able to pick it up for $800. Now, it's time to start gathering parts and information for this swap.
Oh.... and if anyone will be needing a 4.0L on down the road in a month or two, I'll have one that I will be selling.