Not exactly familiar with the rear ends in these trucks and I can tell it's more than definitely been replaced before.

Has a 10 bolt cover and that's about all I know.



Pretty sure it's been apart before, and had the gear ratios changed. it's a 4x4 and i'm pretty sure it had 3.92 gearing done to it, maybe shorter and I'm looking to put 3.55's in it to bring up my gas mileage a little bit on the highway.

Main reason I'm replacing gears is one of the spiders sheered. Any help greatly appreciated.

 

It's an 8.25" open rear end, not limited slip. You should have had a tag on it with the ratio.

You'll need to do the front as well if you're changing ratio's. I doubt you'd get much better mileage, the ratio change isn't that much.

 

Get your build sheet and see what it came with.
http://www.dodge.com/wccsapp/univers...ull&category=R

Spending all that money on doing front and rear isnt gonna work out. You are talking about little rpm difference. Would take you years just to recoup your money. If you are that worried about it then slow your speed down, that will help. Mark the tires and spin the driveshaft and see how many times it spins to 1 rotation of the the tires. Then you can figure out the ratio. Thats if you dont think its stock

 

Since the cover's already off, I would just read the ratio off the ring gear. Or, if it's not stamped on the gear (unlikely), you can just count the teeth on the gears and divide the number on the ring gear by the number on the pinion to get gear ratio.