I'm going to check out these aftermarket Ring & Pinion parts. The pictures he posted show a Nitro Gear box and what looks like a C8.25" axle which works perfect for my application. If there are no part numbers will I be able to count teeth on the ring gear to determine gear ratio? Also, how can I tell if it's for a HP or LP Dana 30?

Sellers ad description:

Selling parts for a jeep xj
Rear axle
Unknown gear set front and rear
Brake calipers
2in lift blocks
$200 takes it all

 

The ring in the plastic bag and the pinion next to it is a reverse-cut/high pinion D30; you can tell because the teeth flow counter-clockwise and the pinion is straight (non-tapered). The gear on the carrier in the back looks to be the same size, so I'm guessing it's a low-pinion set as the teeth are flowing the opposite direction and it doesn't look like an 8.25 carrier, but it's tough to be certain because I can't see the detail in such a small pic.

Hard to tell on the ratio, because 3.73, 4.10, and 4.56 all have 41 teeth on the ring gear. You'll need to know how many teeth are on the pinion to figure that out (3.73 has 11, 4.10 has 10, 4.56 has 9).

 

I went and checked it out. It was almost what I wanted but not quite. Chrysler 8.25 and Dana 30 reverse cut complete kit brand new but 4.88 gears, I want 4:10. He even had the 3.73+ Dana 30 new carrier for the different ring gear depth but I can't deal with that ratio

 

Looking into Liberty / TJ 3.73s now to keep cost down