GMC 3.73 vs 4.10 Gears for Towing

[Cajun Po-Boy]

Looking for some wisdom on this question as I debate making the gear swap ( truck paid for and I'm only a weekend camper).

After running the math between the two gear options ( maybe another better gear option?) for my 2009 GMC 2500HD CC 2WD 3.73 Gear, auto Trans w/ 6.0 gas I configured the following:

With 3.73 gears ( includes 20-25% safety margin):
Max pin weight-2000lbs
Max trailer weight-8000lbs

With 4.10 gears (includes 20-25% safety margin):
Max pin weight- 2440lbs
Max trailer weight-9750lbs

I want to open up our options for more floor plan layouts and sizes and not sure if this is the way to solve this!

I open this up for anyone with experience to help me understand what's right or wrong with thinking! /.)

[tmh462]

I replaced the 3.73 gears in my Silverado with 4.10's. I immediately had a problem with the ABS and ECM. and had to have the truck towed to a GM dealer, where they refused to reprogram the computer for the different gearing, since it didn't come from the factory that way. After calling another GM dealer, and getting the truck towed there, they reprogrammed the computer, and I had a lot better off-the-line acceleration, and the truck didn't downshift as much going up hills. I felt the increase in capacity was minimal, though noticeable. I also lost 1 mpg not towing, and gained maybe a half mile per gallon towing the same trailer.

[Twisty]

It is not the way to solve it.
The only way to increase the factory numbers is to have the truck re-certified after mods.
My truck is rated to tow 7700 lbs with the 3.55 gears. The same truck from the factory with 3.73 gears is rated to tow 9300 lbs. If I switch gears, my truck is not rated to tow 9300 lbs. The factory tow ratings stick.
I would have to have the truck re-certified somehow and I don't have the slightest idea how to get that done.

BTW, the max pin weight/payload can not be increased with a gear change.