I periodically tow a trailer around town and I've got the 5.4 with 3.31 gears. I put larger tires on (265/75/16) and there's a noticable difference in how it shifts around on long hills.

The max loaded weight of the trailer is 7000# and I will be taking it fully loaded on a several hundred mile trip next month. I never tow in overdrive but I'm putting a new ring and pinion gear set on and I'm wondering is there a point where you put a high enough gear ratio on, say 4.56 that you can use overdrive when towing?

Thanks,

Tim

 

Mine's got 3.55's and my boat, depending on gas, water and gear, weighs at least 7000#. I tow in OD without any problem.

If you haven't adjusted for the taller tires, not only are you reducing the effective gear ratio, it may shift weird etc. However, if you're replacing the gear, 4.1 or 4.56 would be great. You'll still need to compensate for the tires and next the new gears. If you've got a chip like SUperchips, (as I do) you can have all that done in the program.

Good luck.