GMC Bill

Thanks for your response Formula Bruce! I use a 16,000# trailer, so based on the numbers you provided, I'm good to go, legally. I travel in some hilly country locally and make a round trip on I77 thru the mountains in West Virginia. So, sometimes, the 6.0 gas struggles a little bit. I'm thinking the 4.10 gears would help with that. Thanks again!

I have a 2012 GMC 2500HD Z71 Extend cab 6.0 gas with 3:73 gears in the differentials. It's factory rated to pull 9,800#. I need to be able to pull 12,000#. Should I have the differentials upgraded to 4:10 or go to 4:56? What should I expected the upgrade to cost? Any positive input appreciated.