What rear-end do I have?

[ALaverick]

Hello all, and thanks in advance.
My ‘08 1500 is a daily work truck, towing a 5000 LB landscaping trailer daily, and occasionally a mini excavator (probably 9000 lbs). About a month ago I noticed a clunking noise, and felt a slip in the rear end when accelerating from a stop and turning. When I jack up the rear and manually spin the tires, they both turn in the same direction. I’m assuming the limited slip is frozen (locked) and will possibly need rebuilding (could just be something jammed in there).
My question is how do I determine what rear end I have and what gears, before I order parts, it’d be nice to know. I didn’t think that’s trucks had Dana axles, so I assume it’s just a 9.25 or 9.75 (but don’t recall how to identify the difference). Also, if it has 3.55 gears, I probably should switch to the 3.92 while I’ve got it open, but again, not sure how to tell (I bought it used and don’t have a window sticker).
Thanks again.

 

[Bloody_Knuckles]

Plug your vin in here: https://www.vindecoderz.com

 

[ALaverick]

Well, that was easy. That’s really good to know. Thanks Bloody_knuckles!

 

[RoadRamblerNJ]

Well, that was easy. That’s really good to know. Thanks Bloody_knuckles!

F.Y.I. The link Bloody_Knuckles sent you is good info on how your vehicle was built by FCA. Just remember, it will not tell you if any mods have been done since then. Rear gear changes are fairly common.

Unless things have changed when I wasn't lookin', If you get under her, in Neutral, count how many revs the driveshaft makes for one rotation of a rear wheel.

3.21's = 3 1/3 revs.
3.55's = 3 1/2 revs.
3.92's = just shy of 4 revs

 

[HemiLonestar]

Stock 1500 rear that year = corporate 9¼"