I am currently running an AMC 360 5.9L in my 1985 jeep cj7, this engine has 160 thousand some odd miles on it and gets 13mpg on a good day downhill.
The driveline consists of the AMC 360, 3spd man., dana 20 transfer case, AMC corporate 20 rear and Dana 30 front. The jeep started its life as an inline 4cyl AMC so it came with 4.10 gears. it is currently sitting on 35 12.50 15 ProComp M/Ts and a 6' spring lift (no shackles, blocks, etc.) just increased arch in the springs.
I am currently looking at a 91' dodge with a cummins 12 valve, 5spd man. I have seen pics of 6BTs under the hood of cj/yj/tj jeeps so it will fit, although it will be tight.
Due to the length of the engine i am considering relocating the radiator and running electric fans on it in order to be able to get the engine off the firewall a little. i also know that the engine weighs 950 some odd pounds plus tranny etc. with the arc in the springs and the brick-like ride i have with the v8 i am convinced that the suspension will be the least of my worries. my primary concern is frame reenforcement as well as mount placement, engine height, etc.
any hints tips or advice would be appreciated.
i have looked around on this site for a while and havent found too much in the way of people putting 6BTs in CJs but if the price on this dodge is right and i can go form 13mpg to closer to 25ish it would be well worth it.