i have a 2008 dodge ram 1500 4x4 with a 4.7 liter. im running 33'' tires and i pull a 34 ft. camper. what gears would be the best to put in .3.92 or 4.10?

 

Of the two, 4.10s but with a 545rfe transmission I'd go right on up to 4.56s, with basically two overdrive gears, RPMs won't be up bad enough on the highway to cost you much in fuel economy but the low end pull will be dramatically better then even 4.10s. Oh and if your running 20" wheels, ditch them for 17s - would make almost as much difference towing as the gears will. There's a reason 2500/3500 trucks come with the smallest wheel that will clear the calipers (17")...

 

Absolutely what Hammer said... 4.56's without question!