I want to put a passenger drop D44 in a 91 YJ (D44 rear also). The AX-15 tranny has the 23 spline output needed for the D300. Will I have any issues using a GLO clocking ring? It looks to be a straight bolt up. Am I missing anything?

you should be good to go... the novak website has tons of info on what works and what is needed....

You will need a 7/8" clocking ring just because the AX15 output shaft is that much longer than CJ transmissions.

CJoffroad sells a nice clocking ring/spacer kit that I used when I ran an ax15 to a D300.

http://cjoffroad.com/AX-15adapter.asp

Sorry to highjack but it's relevant. Looking at the cost of the flip kit, the cost of the 4:1 kit, and the case itself is it cheaper/better to get a 4:1 for the 231? I have never used a vehicle with twin sticks so I don't know how to put a value on that. If you are looking at 1200 plus either way does the twin stick outweigh the ease of the 4:1 kit for the 231?

twin sticks are great; but i would rather have a 4:1, especially with an automatic.
but, you can always go back and put a 4:1 kit in later.

I have an AX-15 with the 4.0 and 4:10s rolling on 37s. I need help with gearing to crawl. I have done the axle swap (44/60) and ultimately plan to be 4 link in the rear, 4:88s, V-8, and transmission depends on the engine. I may swap in a 360 and leave the 5 speed or get a SBC/BBC with a TH350/400. I don't think I need a 60 out front but it is so hard to find a gear driven case with a driver drop, without dropping a couple grand on an Atlas. I may just gear the axles to compensate and keep the 231.

Screw flip kits , I had one at one point. Use the stak 4x4 replace a case. Its just a simple drivers drop Dana 300, uses stock parts, accepts 4:1 kits, way stronger then the 231 and you can still twin stick it. Hell if they were available when I Was doing my axles, id still have a drivers drop front axle at this point.