I will bet I would get better "TOWING" mileage with the 4.10's than 3.73's with my combined 33-35K. Solo the 3.73 would be a bit better. Truck is for TOWING and it is what it is solo.
28K and under no question 3.42 with AISIN can't be beat!
When I posted my specs on the TDR in 2012 with my 11 HO towing a combined 27-29K with 3.42's you would have thought the sky was falling! But it performed GREAT with one exception, I had to take it easy on grades starting out. The AISIN cures that problem with it's lower starting gears. I have towed with my Son's 15 3500SRW AISIN 3.42's combined about 27-28K and it took off on some good grades with ZERO issue.