I'm starting another project, I've got my 86 2 door with the ****ty little 2.8 v6, I'm ripping it out and dropping in a cummins 4bt, any advice?

 

I would pass on the 4bt they are getting pricey now and 700lbs is heavy for its size.I would look in to the vw diesel swap its been done on a few wranglers.They even make a adapter kit for the jeep sticks.Another option the gm 62/6.5 uses small block motor mounts but still as heavy as the 4bt tho.

 

No real advice, but you might also look at the Mercedes OM617. I've been looking at those on CL lately and you can get the entire running car for $1000 or so.

Like andrewmp6 said, at least in my area too, the 4bt prices are getting a bit high.

 

4BTs aren't that expensive. And it doesn't take any effort to get one running no matter what you put it in.
GM 6.2s and 6.5s are not a great choice. I've had them, couldn't ever keep them running. And they lack power. Good fuel mileage is the only good thing about them, my 6.2 K5 Blazer with a TH400 on 33's got 24 mpg.

4BT with an NV4500 behind it would be my first choice.
VW diesel with an AX-15 would be my second choice.

 

my buddy has a 4bt in his TJ. gets high 20s MPG on the highway. go for it.

 

Here a 4bt goes for 2 grand even if it don't run but a 12 valve cummins running is 1500.The reason i bring up the 4bt weight is if you want a rock crawler a nose heavy truck down hill can be a little scarey.The 4bt is 700lbs the jeep 4.0 is 515lbs a chevy small block all cast iron is 575lbs.

 

Good point, all that weight up front could be bad. I've had the rear wheels come off the ground a few times going down hills with just the little 2.5 up front and weight in the rear.

 

Well i have a 40 gallon fuel cell in the back, i think it should help with that

 

Good luck with your project, 86 was the last year of the small engine bay. The firewall was modified in '87 to fit the 4.0. With anything bigger than, say, the VW TDi, you're definitely going to need the extra room.

 

I've been looking at the 4bt for a while, but i have an ls7 sitting in my garage, it's running an f1-a pro charger, i want to go diesel for the mileage, but now that I'm looking at it i might be able to fit the ls7, I'll have to do a lot of cutting and drop in a new Trans, transfer case and may as well do new axles while I'm at it, and bigger tires. Anyone done anything like that?

 

v8 swaps have been done just take a lot of time and money to do.A few questions to ask yourself is how much of a budget do you have.Do you want full width axles or something close to the stock ones in width?What tire size and what trans auto or stick?