Hey guys, hope you're all doing well. The time has finally come. After 25k miles of highway travel, my BFG AT's are as good as shot. I want to upgrade to 35's now, either KM2's or Nitto Trail Graps. What else do I need to get so my performance doesn't drop dramatically? I'm getting new rims. I know I need a tuner. What about these gears everyone talks about? Do I get 4.10 or 4.56? Anything else?



Thanks for your time,
Anthony

 

I would recommend 4.56s with 35" tires. Everyone on here, Troyer and at Randy's Ring and Pinion told me to get 4.56 gears if i went to 35" tires. So i did, and i am very happy with them. If and when you do the gears no matter what ratio, i would also recommend a locker of some type. A tuner helps too, especially the combination of gears, tuner, etc,etc.

 

You wore out BFG AT KO's with only 25k miles? Or are we talking about a different tire? The AT KO's with a good alignment and rotation regularly, have been known to last 60k+ miles. I hope we aren't talking about the same tire.

Do all FX4's have the 3.73 rear? If so, then you will be fine with the 3.73's and a good tuner. That's what I have and have no complaints to speak of whatsoever. I've got the ProComp Xtreme MT's and love everything about them. I had 35's on the truck bone stock and still had no problems to complain about. Now with the tires, exhaust w/ hi flows, intake, and good tune, even less to complain about. Ideally a 4.56 upgrade would be great in the future, but I don't have that kinda coin to drop on both axles

 

x2! My buddy just replaced his set which had 58k miles...on a 3/4 ton!

 

OP...you going with a suspension lift? If not you'll have to get a wheel with around 5.7" of BS...

 

so you recommend getting a whole new rear axle?

 

Not really...just gears and a locker...differential stuff, no shafts.

 

I have an Eaton Detroit TrueTrac LSD in the rear.

That's without regular rotation and alignment. I lead an extremely busy life, especially this past year. I also said they're as good as shot. Ford said all 4 are in the red, but I can probably get at least 5k more miles out of them before I really, really, need to be concerned.

 

Just FYI if you get the Nittos or KM2s, you really need to be religious about rotating or you will get even fewer miles than your previous set.

I rotate mine every 3k when I change oil and at 20k miles now I am confident I'll get another 25-30k out of my KM2s no problem. My friend had the Nittos on his Chevy, didnt rotate much and they got knocked out of alignment...shot at 15k miles.

 

The future holds more promise for regular rotation.

 

The BFG KM2's are a great tire, but I also recommend the ProComp XTreme AT tire. I've had them now since April and I really like them. They are suprisingly quiet, have great wet traction and super deep lugs for an AT tire. The best this is that they come with a 40k tread warranty.

Here is the XTreme AT 35x12.5x18 next to a Nitto Terra Grapp 325/60r18 (33" x 13" wide). The Nitto is mounted on a rim which makes it look even wider).



Side shot:






Anyway, I thought I'd mention them to ya...

 

Thanks Stove, I'll look into them.

 

what size tires do u have on there now?