I'm looking for advice on gears for a 2007 f150 4x4 with a 4.6L. It is all stock. I tow a horse trailer with a weight of about 6000 Lbs.

 

anymore info on the truck would help( stock gears, cab, tire size).
the 4.6 makes most of it power above 3000 rpm, so its best to keep it close to its power "sweet spot"with the O/D off towing. most 4.6 i've seen have 3.55:1 gears which is only rated for 5500lbs. given the weight your looking at 4.10:1 or possibly 4.30:1

my truck for instance is '04 crew cab 5.4L with 33" tall tires pulls ~8300lbs a few times a month, I run a 4.56;1 gear which puts me runnin 2700-3000 rpms at 65 and the O/D off.

 

http://www.gearvendors.com/4x4.html

Overdrive / Underdrive, goes behind transfer case, locks out electronically in 4wd so can only be used in 2wd, like when towing.

Likely more $$$ than you want. If you tow all the time, the 4.10s are probably best with a 4.6 and use Drive.

 

Those unfortunately don't work for our trucks, they only work on vehicles with a speedo cable, since our trucks use electronic sensors it's gonna be a no go on that.

 

It has 3.73 stock gears is it right now.I was thinking 4.30 or 4.56 but wanted another opinion. I towed it from Ohio to Maryland and it did pretty good. Some of the long grades gave it a pretty good work out so I thought gears would help. Getting an edge tuner for Christmas so that should help some.

 

4:56 would probably be a little much with stock tires, 4:10 would probably be best for good towing and everyday fuel mileage.

my 4:56 and oversized 33" tires equal a 4:10 with stock 29" tall tires and love it

 

Maybe so, seems they do have thiis one?

http://www.gearvendors.com/ag4x4.html
But even if it would work, awefully exopensive alternative to 4.10s. If it's always going to be pulling, the gear swap would be the way .

 

nice find, not sure if it will work thou, the 4r100 is completely different from the 4r70/75 transmissions, but are the T-cases the same

 

If you have 3.73's, the upgrade to 4.10's really isn't worth it. The next step up for a 4x4 is 4.56, which is a bit too much with stock tires. I'd probably keep the stock gears and get a programmer with some custom towing tunes to beef up the low end torque.