Without cutting the firewall? I have 28 inches between the bellhousing and the grill. 30 inches wheel well to wheel well. The 231 is basicly a 350 with two cylinders wacked off and I will not get anything larger than that in there.
The point is biodiesel. I don't want more power, you are hanging on for dear life at 55 mph as it is. This jeep is stock other than the newer engine and I want to keep it as close to that as possible.

 

Ah....ok, now I see the angle you are coming from. Correct me if I'm wrong since it has been a very long time since I have seen under the hood of a jeepster, but doesn't it have the same size engine compartment as the same year CJ5? They were offered for a time with the Hurricane straight 6, no? (Not a short engine!) If the best swapability, economy and reliability are the key factors, I would suggest a 4BTA.....height would be the only potential dimensional issue with that engine and it will offer much better characteristics for your particular swap than any other diesel other than maybe the newer 3.3 CTD.

 

This is what it looks like. This is an AMC and the Hurircane was in the Kiaser, but I think it is the same as the cj5. the 231 came out of a 73 cj. If I take this radiator mount out I can gain about six inches, but I would rather not. I think I am going to head out to a junkyard this week and see what I can find, do some measuring.
I know this is a dodge forum, but I would like to thank everyone for being so helpful, I tried diesel garage and nobody there seems able to help. I have a frontier now, but am selling it and want to turn this into my daily driver