There is a CJ7 in West Sacramento with a 5.9L Cummin' in it.
The guy literally started with 30 feet of rectangular tubing and fabbed up a whole new frame for it. He had to stretch the front sheet metal six inches to clear every thing.
Transmission was an NP435, and a D300 T-case. Axles were a 30 front and 44 rear. There was (last time I saw it, about eight monthes ago) no way a front drive shaft would EVER clear the oil pan, with out a lot more lift. I beleive it was already SOA with lift springs.
It sounded killer, and would scoot down the road very fast.
I want to do a 3.9L Cummin' in my YJ. The swap would not be all that difficult. I would maintain about the same amount of horse power, but at least quadruple the torque.
Cummins actually manufactures adapters to mate these engines to most popular trannies, like the TH400, NP435(factory Dodge bellhousing), SM465/420, T18/19/98, and NV4500(factory Dodge bellhousing).
In my searching for this swap, I have found that Cummins West sells Cummins ReCon BTA 3.9L 130HP engines for $4635, plus a $2000 core.
Core engines are available everywhere for pennies(ok, small dollars) and a rebuild kit pretty cheap.
The 3.9L is about the same length as the 258 I6, considerably heavier. With factory Dodge bellhousings, it would be cheap to mount to NP435s or an NV4500. While spring and axle strength would be a concern, I would not worry too much about frame strength with the 3.9L in a YJ. The 5.9L is another deal altogether. Early Dodge pickups equipped with the 5.9L quite often came back to the dealership with one front tire up in the air from the frame being twisted by the torque!!
<IMG SRC="smilies/eek.gif" border="0"> As a result, Dodge beefed up their frames and detuned the engine.
[ 08-28-2001: Message edited by: Robert ]