Not sure what size tires you have, but if you can find some that are about 2" in diam smaller, that equates to lowering your current 3.08 to and effective 3.42! borrow those for a week or so and see how the truck performs etc.
The other reality, I can not remember if it has been mentioned, you may need to figure out what speed you will normally tow on a freeway at, then figure out if that gear rpm is going to meet max speed per the amount of HP you have. My old truck had 4.10 gears, In my case, I could have gone faster up hills with a 3.73, as my truck had the hp to go faster in 3rd, ie gear below direct when I could not hold 4th. BUT, since the 4.10s limited me to about 38 or so at 2500 rpm, I could get to redline 3200 in 3rd, I was slowed to 38. With 3.73s I could have gone about 42-45 at 2500. Hence also why the NV5600 was a better towing tranny than my nv4500, as the gear below direct was a 1.3x in the 6sp vs a 1.6x in the 5 speed.
Reality is, as noted, gear ratio's as not as cracked up as they are taken for.
ANother fellow asked if he should change out ratios from a 3.42 to 4.10, yet he was pulling local hills just fine. I pointed out comparing his 3.42 rig with a muncie 4 sp he had vs my 4.10 NV4500, his final rpm were the same at 60, yet we both had an overall low of 24-1. His rpm shift splits were wider. But his final and low ratio were about the same as mine. So reality is, he had no reason to change out his ratio. His axel ratio was the perfect setup for that trans. High gear for him was 1-1 vs me at .75-1.
There is more than one way to skin at cat when it comes to what is the best gear ratio per say for towing etc.
Marty
