Topic: Question about building an AX15 / R15x hybrid

[comptiger5000]

I've got a 98 Jeep Grand Cherokee with a 5.9 in it that I'm looking to manual swap at some point.  I was thinking of putting in a Terminator AX15 (I'm not sure how well a stock one would hold up), but I need a better OD gear than the .79:1 (my current auto trans has a .69:1 OD, and it could still use a taller gear on the highway, it pulls 7% grades at 1750 rpm doing 60 in top gear no problem). 

I've got 3.73s in the axles (which I'd rather not change) and 29.5" tall tires.  I'm curious as to what combos are possible while retaining either an AX15 input shaft (or one that I can use with some clutch setup that I can get to work with that engine) and still bolt up to the Jeep t-case (NV242).  The .63:1 OD from putting an R150/151 OD gear into an R154 would be awesome, and the 1st gear in the R154 is manageable with the 3.73s.  However, being able to retain the 3.83 1st on the AX15 would be nice for towing. 

Any suggestions on what combos I should be looking at? 

[comptiger5000 [OP]]

After some more research, it looks like the best option is pretty much an R154/AX15 hybrid, using the R154 gearset with the 5th gear from an R150/151 (the AX15 5th might work too, I can't find anything on that, but it also might be a little too tall).  Is it possible to do this and have it bolt up to the engine using the Dakota 3.9 V6 / AX15 bellhousing and still have it bolt up to the Jeep t-case on the back, and preferably retain the AX15 shifter position? 

[Goose0850]

Don't know if you've figured this thing out yet or not, but here's a link that might be helpful...

http://www.pirate4x4.com/forum/jeep-hardcore-tech/667318-gm-metric-v6s-your-ax15-r150f-jeep.html

It looks like your gear swap might be possible.

Also, what year did your 3.9/AX15 bell housing come from?  I know they were in early Dakotas, but can't seem to find what year the cut-off really is when they switched to the NV3500.