I have a 97 3/4t, 454, 4L80, 4.10's. When towing in overdrive RPM is appx 2350 at 70mph, in drive I'm at 3000 rpm. I'm thinking about changing the ratio to 4.56's or 4.88's to raise rpm in OD or should I drop to 3.55's or 3.73's and just tow in drive. I pull appx 7500 lbs from Texas to as far as Utah and Colorado. Currently OD just seems to work the truck too hard and 3000 in drive seems a little hard on things. Seems that 2750 rpm at cruise would be more of a sweet spot. I'm open to suggestions. I have intake, exhaust, and a Westers tune.

Drive faster :flipoff2:

Tried that, truck just doesn't have the balls at 80mph. I even bought a camper shell to help airflow over the Jeep but made now difference.

Why would 3000 rpm hurt the motor at all? Or anything other than a little mpg?

Don't care about mpg, just seems like alot of rpm to run at for long periods of time. It gets 10 mpg towing regardless of which gear your in. Truck has 60,000 and will be around for a while. Gears are cheaper than a car payment. I thought some duallys had 4.56's and hopeing to here from someone towing with that combo.

Don't care about mpg, just seems like alot of rpm to run at for long periods of time. It gets 10 mpg towing regardless of which gear your in. Truck has 60,000 and will be around for a while. Gears are cheaper than a car payment. I thought some duallys had 4.56's and hopeing to here from someone towing with that combo.


So 3,000 rpm is too high.....but you think 2,750 rpm is fine? And you are willing to spend the time and money to swap the front and rear axle gears for 250 rpm?

Anyway, back to part of the original question. I would definitely suggest going to lower gears (4.56 or 4.88) to retain use of OD versus higher gears IF the main emphasis is on towing. If you DD the truck than something like 3.42/3.55 would probably work good, but if you mainly just tow might as well be able to use all 4 gears in the trans.

Whats the tire size as well?

Just run factory 245 load range E's. It's only 2wd. I agree 250 rpm isn't much. Maybe I should be after 2500-2600 rpm. The big question was what gear to be in and to then gear accordingly. 14 Bolts are easy enough to work on and I don't mind doing it, I just want to do it once. Seems like 4.88's would raise me to 2650 rpm or so in OD. If rpm is too high I can bump up in tire size to adjust.