OkaloosaFX4

The 5.4L 3V is a dandy monster torque at low rpm engine. It grunts like a champion and is why Ford hauls better than most during those times. The 3.55 gears paired with 35s will work just fine, as I got away with it for a while. I wanted more performance so I went with 4.56 gears on both diffs and the truck is a whole new machine since. The smaller V8 is not the same. I can't imagine how your gas mileage is hurting with those 35s. The driveline will be taxed, but I firmly believe you won't damage your tranny so the sky is it falling. I think you have to ask yourself if you want better performance and better economy and then make the financial commitment to make that happen.

A lot of people make that commitment for bigger wheels and lift kits, but don't want to invest in gears and tuning. Then they turn into adamant advocates of "oh you don't need all that -you'll be just fine". I should know because I was one of those people and I would preach from the hilltops on this board about it. After my 4.56 gears and the tune, let's just say I have changed my tune. Single best thing I did for the enjoyment of driving my truck was adding gears and the tune.

My .02.

OkaloosaFX4

I have the SCT X3 with customs tunes from Mike at 5 star. PM me and I will tell you all about it. Unbelievable performance gains... Mike can create safe power gains that will make you never want to trade your truck in for something newer.

rbbell0198

The SCT tuner is nice great power even running the 87 tune. Gas mileage stays consistent. I love it! Looking to run the 91 tune or 93 tune soon.

Call-_Me-Jordan

Anyone running a 99-03 4.6L 2wd with 3.55s and 285/70/17?

BigDaddy750

I've got am 07 with that setup...and it is pretty slow to take off from a dead stop

Call-_Me-Jordan

So how is towing?

BigDaddy750

It's capable, but a little slow. I live on the plains of west Texas, so hills are nonexistent. It tows fine on the highway under 70mph. That said, I am planning some 4.10 or 4.30 gears this winter to get a little pep back. The most I've pulled is about 6500 pounds and I've had well over a ton in the bed. It's a good solid truck with enough power for most applications without the engine problems that can come from the 5.4.

cliffuhl

i just bought a 2012 xlt 5.0 w/off road pkg 3.73 ,19-21 mpg on hiway avg 17.8 city/hwy im very happy with it so far.

Call-_Me-Jordan

I wish I could find 3.73s

smurfs_of_war

Go 4.10. The difference between a 3.73 and 3.55 with a 4.6L is going to be far from earth shattering. If you're going to regear it- 3.73 is almost moving laterally.