Well If Your Stickin' to Relative Sock Tire Size.. I Think 4.10's Would Suit Your Needs. I Went W/ 4.56 Because I Knew I Was Going With An Over sized Tire.

Once You Get Your Gears I Bet You'll Fall Back In Love With Your Truck. The 4.7 Isn't A Bad Motor, It's Sure Not A Hemi, But They Are Good Motors. The 4.7 Motor Is A Benz Motor and I Have Seen Reports of Them Clicking Over 200K Before A MAJOR Overhaul. I Haven't Seen That In A Motor Since The 4.0 I6. Thats Just My .02

As Far As Performance - Do Your Gears, CAI, Exhaust and You'll See A Difference that Will Have You Loving Your Truck Again.. Thats How Mine Went.

Jet Performance offers A Chip (Stage 1, Stage 2), I However Finally am Convinced On Stage 2.
On This Fourm and Others, I Have Seen Many People Disappointed In Stage 1's Performance, Ruling that Your PCM Ends Up "Learning Around It" Anyway. Stage 2 However Requires Premium, but Shows Great Performance +'s. I Convinced My Buddy To Buy One (For Once I Wasn't The Gunnie Pig) and I've Gotta Say.. I Was Impressed. With The MPG Gains The Chip Claims, It May Outweigh Additional The Price of Premium. (At A Bar, On A Napkin.. It Looked Good. LoL)

 

I’m guessing that your larger than stock tires are part of the problem. My truck was born with 245/70X17 tires. When I bought it there were 265’s on board. The original gears are 3:55’s. The 265’s were “large� for their size and equal to a little more. I did not want to change out both the front and rear gears along with the spare to the same size as the 265’s. I decided to replace the tires with the original 245 size. I purchased LT245/70X17. These LT tires are rated at 3,000 lbs each!

265’s would need 3:92 rear gears to be on equal terms with the stock size tire. I know a lot of people swear by the lower gears and if that is your wishes fine. After the change to the stock size tire I don’t have any complaints. The truck was never really happy on the highway (towing or not) with the larger tires as far as power and driving ease. I also tow about 4,000+ lbs regularly with an additional load in the bed at the same time. Yes, I tow with the overdrive off – it knocks down the final drive ratio a bit.

As far as gas mileage. Don’t believe all you hear. But my true mileage did go up with the change to stock size tires.

 

It is much cheaper and simpler
to just lock out overdrive top gear
when towing or climbing hills.

Fitting slightly smaller diameter tires
that are lower rolling resistance (see FAQ)
will improve both hill climbing ability
and MPG (slightly improved aero as air dam gets closer to pavement)

When you install 4.10 or 4.56 or 4.88 differential gears
you are essentially turning overdrive top gear (5th)
into what your 4th gear is supposed to do.

The truck will then not shift as it encounters hills
but that also means you are getting worse MPG
on flat and downhill sections of highways.

Chrysler engineers want you to use 4th gear
when towing and hill climbing
because as a 'direct drive' one to one ratio
(gear ratio is 1.00 instead of overdrive's 0.67)
as is like a 'straight shaft'
and is about 4% less friction than any other gear
...which improves MPG and lowers the temperature rise of trans fluid.

There certainly is a group of drivers that want their pickup
to cruise along the highway either loaded or unloaded
in only overdrive top gear
and never downshift at all.

While many drivetrain engineers have been known to mutter 'morons' under their breath about these owners,
other engineers have invented CVT transmissions (Nissan & D.A.F.)
and MDS (GM, Mercedes, Chrysler, Honda)
to keep them happy in the past,
and soon the Chrysler/GM/BMW joint effort of 'two mode hybrid' drive
with electric motors inside the transmission will be available to boost
torque on hills without a shift change.

 

Very good to know. When towing I listen to the trans and if it starts to do a lot of shifting I will turn off the overdrive. With common driving and not towing I use the overdrive.