MaxedReflex

I've got a '14 5.0L and looking to switch my rear diff gears from the stock 3.31's

Looking into 3.73,4.11 or 4.56

Running 285/70/17 MTs (33s)
Next tires are going to be a 33x22 street tire

Any opinions on the specific ratios?

Manuellabour247

For the tires you're thinking about, I'd personally go with 4.11's. That's unless you're thinking about a bigger tire within the next couple of years, then I'd go with 4.56's right out of the gate. While your highway mileage will suffer a little bit, around town should be close to the same even with the heavier tires.

MaxedReflex

Yeah, I was leaning to 4.11. To make up a little gas mileage, but right now it's a debate on lowering the back and Roush kitting the coyote or lifting it and running 35's which I could run even 4.88's.. So much choices! >.>

\m/(^.^)\m/

Manuellabour247

Even with 35's I'd stick with 4.56 gearing. Still gives you greater mechanical advantage over stock sizes, but not so much so that your gas mileage drops like a stone in the abyss. Lol. 4.88's would be more for 40+ I would think. But it's all really what you're wanting to do with the truck. If you're looking for break neck power, then the 4.88's will be better.

jedeckert1984

I plan on going with 4.56s, optimal gas mileage and performance. There is a guy a with a 2013 FX4 running the Stage 3 8in Kit with 4.56s and 37s on 20x12, he gets with a tune 17-18 and can fry the tires off from a stand still.

SteveLord

I asked about higher gears before and a guy at this shop tried to steer me away from higher than 4.10 because of always being at higher RPMs or something?

Manuellabour247

If it were an Eco I'd agree with that guy, but the 5.0 likes to rev. It's sweet spot for perfomance is higher in the RPM range. Shorter gears (higher numerical value) are more forgiving that way.

InDaRed2

I would go 4.11 max. Wouldn't go 4.56 unless you were going 35s.

Had 4.56 in my old truck with 35s and it would get better city milage than on the highway cuz it was at 2500 rpm at 70...

sloate9471

I have a 3013 SuperCab STX with 3.31. Will going to 3.73 allow me to tow a heavier trailer? I installed a Blue Ox underbed Gooseneck hitch.

NASSTY

Your truck will tow better with lower gears. But the tow #s that your truck can legally tow won't change. If your truck was rated to tow 8k lbs , your limit would still be 8k lbs.