Should I change from 3.73s to 4.10s
 

Gents,

I've got a 2001 1500 extracab, 4x4, 5.3, Z71 that has a 3.73 ratio in the axles. I've been towing my travel trailer which is 5600 lbs and have noticed a drastic reduction in performance on the highway. Should I change over to the 4.10 gear set? What would something like this cost? Should I buy a used set or pay for new? Any recommendations would be appreciated. I don't want to shell out that kind of money if I don't need to.

I have 4.10's and I really like them. I don't tow much now but honestly the gas millage isn't that bad even on the highway and stuff. The performance is great weather I'm towing or now. I have some snowmobiles and am looking to get a boat the summer and I'm really going to enjoy having the 4.10's when the fishing season comes around!!! If you tow a lot they might be a good idea. I have no idea on the cost of making the switch but if it was me switching I would probably go with new ones mostly for peace of mind. I'm not the biggest truck techie but thats my two cents. Good luck!

Thanks for the comments. It looks like about a $1300 investment (parts, labor, computer tune). I just can't decide whether it will be worth it for me. Everything I have read says that the 5.3's can run at a high RPM and when I'm heading through the White Mountains there are plenty of hills which means I'll be pushing my RPM's up there. If the gearing will make that big of a difference, I'd be willing to make the change. I just can't find any info that directs me either way.

Thoughts???? Anyone tow an RV out there?

5600 lbs is quite a bit of weight for a 5.3. remember that peak tq on the 5.3 is around 4000rpm or so. that said, 4.10's will help but it wont make that much of a difference vs the 3.73. if you had 3.42 i would say do it. if you have a 4 wheel drive you will have to do the fronts as well. front rear gears usually run about $1400 installed where im at.
i would just call nelson or blackbear performance and get a custom tune and see if that helps any. you can get about 20hp to the wheels with a tune. if you plan on running bigger than stock tires then the gear swap would be good.

good luck