Where on the truck do I find the Gear Ratio?

 

That is a good question, might be on the sticker inside the door, but it is probably a code.

08, you bought it new? If it is not in the window sticker over in the optionsthen you have 3.55s as that is the standard.

 

I know manufacturers USED to put a tab right on the differential off the bolts stating the gears. Not sure if they still do or not tho, wouldnt hurt to take a look.

 

I have a 08 Bighorn Hemi and it was on the window sticker. I have the 3.92 gears.

 

If it has 20" wheels, it's most likely a 3.92. Look on the glovebox door, or look for a tab on the diff. It'll probably say "39"

 

PM me the last eight digits of your VIN and I can tell you what you have....

 

Thanks for all the info...I will check....