I would have to guess you have the 3.55`s. I`m assuming you want to go to 3.90 or 4.10. 3.90 was a factory option. If you have 4WD you have to do front and rear. It could get expensive! However it will make the Durango perform much better. If you want to keep the Durango it is a worth while mod.
I had a Dodge conv van with the 5.9L and 3.55 gears. I went to 3.90`s and it was a huge improvement! solo hwy mileage went down, but around town and towing mileage went up.
Its not cheap if you have to pay to do it, but from a performance stand point well worth it!
Wife Kim
Son Brandon 17yrs
Daughter Marissa 16yrs
Dog Bailey
12 Forest River Georgetown 350TS Hellwig sway bars, BlueOx TrueCenter stabilizer
13 Ford Explorer Roadmaster Stowmaster 5000, VIP Tow>
A bad day camping is
better than a good day at work!