nate_o23

Well I have been working out the particulars for my 4Bt conversion into a Jeep Grand Wagoneer. This is going to be my wifes daily driver not a rock crawler or tow vehicle so I am mainly interested in reliability and MPG. I originally going to go with a 47RH but due to the complications of controling the lock up and getting the tranny to mount up to the stock NP229 made me rethink it. The GW originaly came with the AMC version of the 727 so the diesel 727 should bolt right up to the NP229. Worse case I might have to use the AMC tailshaft and rear housing. My question is how different is the Diesel 727 from the standard gas version?? What all am I going to need to bolt a 727 up to a 4BT?? Starter? Flex Plate? Adapter? Thanks.

wannadiesel

I think you nailed it right there.

What gears are you planning to run in the axles? If this thing has normal size tires the top speed is going to be low unless you can scare up some gears in the 3.0 range.

JD730

The bell housing is bigger and the internals are rated for more torque. Basically they are similar, but they won't interchange(case is different), I'm pretty sure alot of the internal parts are similar.

Your going to need a bell housing adapter from a 6BT out of a dodge, along with the starter and flexplate.

mooktank

Anything that bolts on the back of a 6bt will bolt on the back of a 4bt so yeah just take what's attached to the block/bell adapter and it'll bolt up. Good luck with the project the 4BT is a good engine but shakes around quite a bit. I'd recommend hydraulic engine mounts.

nate_o23

Forgot to add the 727 will let me keep the stock gears which are 2.7. According to ratfactor.com that means with stock tires the 4bt will be turning 1782 rpms at 55mph, which is pretty good. Wouldnt want to tow with those gears but it should be fine for a grocery hauler.
So it sounds like I definitley need a diesel 727 if the cases are different. Danm I was hoping to use a gas 727 I had layng around! Also looks like I need all the other stuff that goes with like adapter, etc...

wannadiesel

That is an excellent gear selection for a trans with no OD and a low revving diesel. I figured the stock axles on your Wagoneer would be in the 3.5-3.7 range. You'll be surprised how well it will pull, the torque does a good job making up for the lack of gear.

jughead

just a little off topic but torgue is what gets the vehicle moving. in my 82 with 3.21 gear i never use anything but 3rd in normal driving. it is a 6 but with gears the 4 should be great. if i remember correctly, the rear drum and band are diff. fooled me they looked the same. gov. has brass weights. can use gasser valve body but shift timing is diff. i think i used everything from rear drum out in the diesel case. of course one uses the diesel converter. been nearly 5 years since i did this on my 82. memory "could be off slightly". absolutely no problems with trans. since installed.