Auto Parts: 1998 dodge durango rear end unit, dodge durango, salvage yard

Question
I have a 98 durango and I need to replace the rear end but I'm getting different stories on what I need. Called the dealer and they said I have a 392 Chrysler light duty with anti spin lockup. I was told by a salvage yard that it is either a 355 or 390 with it being a 12 bolt on the case. So I'm confused because know one can find a 392 with 12 bolt case and I keep getting told its a 390... So does any one know what I really need.

Answer
I used to own a Durango also.  You can check the codes on the sticker in the glove box to see if you've got the 3.92 rear.  If your vehicle wasn't delivered from the factory with the towing package, it's got 3.55's.  If you have the towing package you've got 3.92's.  You can also look on the rear end for a data tag with the numbers on it.