5.0GN tow

I pull a gooseneck with my 3.55 geared 5.0 all the time and it's at least 1000 heavier than yours and it does just fine. Buy 3.55s and don't worry about it.

Wannafbody

3.55 will tow fine with an EB but since the torque comes up later on the 5.0, I'd suggest the 3.73.

Mike Up

I have driven both the 3.73 and 3.55 trucks in daily driving and didn't feel all that different. I think the main difference is to help keep the engine temps down by working the engine less when pulling heavier loads.

I feel the real tow ratings are low balled to make the 3.5L Ecoboost look better.

You really shouldn't have a problem finding a 5.0L with a 3.73 differential as that gear is required to tow 9300 lbs.

There's many people as myself, that didn't want a turbo engine that had condensation problems, to tow with. So they bought the 5.0L with the 3.73 differential. You'll just have to do some searches. They are out there, and probably in demand, so it may be a bit harder to find one.

You could always look for the 5.0L with the HD payload package also as the 3.73 gear is required for that truck but with a limited slip differential, not a locker.

BTW, most FX4s come standard with only a 3.55 differential, so even with them, the 3.73 locker is an option. I think 2011 was the only year that the FX4 5.0L came standard with the 3.73 differential.

5.0GN tow

Trust me a 3.55 will be fine. I have pulled many 5% grades with mine loaded close to 8k and it does it very easily.

A7B2FX4

Not all FX4 came with the leather/fancy interior. That was an option in the FX4. If you're towing in the mountains then the EB not the 5.0 is the way to go. If you don't like the EB then the 6.2L is way better than the 5.0 for towing but they are rare as the 3.73. Axle code is on door jamb label. Not in the vin code.

Mike Up

Just throwing this in as pickuptrucks.com really liked the 5.0L and chose it over the Ecoboost in towing under 10,000 lbs.

LINK

I mostly agree but if I were towing over 9000 lbs, or maybe even less, I'd be looking to buy a 3/4 ton or 1 ton truck.

5.0GN tow

There is about 100 RPM difference between 3.73 and 3.55 for a given speed so really not enough to worry about.

king nothing

I don't know about anyone else but if i was looking at towing a 6400lb gooseneck I'd be looking for an HD payload, or at least a max-tow equipped truck. You're going to have at least 1200lb of hitch weight. Lots of standard Screws only have 12-1500lb of available payload, leaving you with very little, or no, payload remaining for passengers or anything else in the truck

Mike Up

It's not about the rpms but the torque multiplier to create more torque, and work less. Same thing with a 4WD low gear, more torque. The 3.73 will have a 5.07% gain over the 3.55 gears. with 380 ft lbs, that equals 19.3 ft lbs more with the 3.73 gear. Not huge, but may keep temps within their specs to tow heavier.

acadianbob

And it is also about the torque curve of the engine. The EB can handle a lower numerical rear end better than a 5.0 because of the torque curve of the EB.