It would be much cheaper to re-gear your current truck than jumping into a new one. A 3.73 or 4.10 ratio would help immensely with towing at a fraction of the cost.

 

What gears are in your truck now?

What are you towing that is 7k lbs?

How are you towing it?

There's a lot of factors in towing something, more than just brute power.

I tow my ~6500lb boat just fine with my truck that has the 5.0l and 3.55's but I don't use cruise control when in the mountains.

 

Using Smaller Tires & Wheels is the Best Option. It will also make your vehicle more fuel efficient especially in city driving.

When using larger or smaller than OE tires, the PCM needs to be
re-program to correct the speedometer to shift correctly.

The Heavier E150(Wheel 15") can tow much better than F150(wheel 17")
(same engine, transmission & axle) You will not see a huge difference when the AC is ON because E150 4.6 V8 don't have a Wide Open Throttle (WOT) relay to disengage the AC Compressor. E150 is more fuel efficient than F150.

Look at the chart below

 

Deleted post

 

Looks like I may have come across a deal!
2014 F250 crew cab Lariat. Fully loaded, leather, sunroof 6.2 gas, 4x4 and 3.73 rear axle. $41k
....... It has 1700 (seventeen hundred) miles on her!
It's not a diesel, but damn, this has to be a steal!

 

Doesn't sound too bad. If you want a diesel keep looking. I just got a 11 fx4 crew cab for 29k. It has 102k on it but was driven by a 70+ year old couple with all maintenance done at dealer. I saw them trading it in. Not a single oil spot or anything under her.

 

BS, Low end torque is easier to achieve with a dual overhead cam with variable cam timing, never seen that on a overhead valve. The 5.0 has more low end torque in a truck than car, it's how they design the cam profile not that overhead cams produce less torque. The Dodge Challenger SRT Hellcat makes more torque because it's supercharged, not because it is overhead valve. Put a supercharger on a ford 6.2 and it's by-by ecoboost.