EDIT: I ran the truck at various speeds and had my GPS up on the dash above the speedo. I now have a 15% error on my speedo and odometer. This was 10% with the 285's. At 50 MPH on the speedo I am traveling 57.5 on the GPS...

So when figuring my gas mileage I will add the 15% back on before doing the math. I was averaging a corrected 13.5 MPG with the 285's, 17 on all highway and closer to 11 in city or with a load or the trailer. I will post up what I get after this tank, I filled it tonight.

The truck is a stock 97' 3 door 4X4, auto, 4.6 with about 140K on the clock, stock air filter setup but 2 HP cats instead of the 4 stockers and a custom exhaust 3" back to the single dual 2.5" outlet muffler.

I had 285's on my 97' F150 3 door. The truck is torsion twisted with custom 5 leaf packs in the rear for a level ride. I scored a set of 34's 325/70R16 Brand new NITTO TERRA GRAPPLERS for $600 out the door mounted and balanced. This was the last set of three the shop had and he wanted them off the floor. What do these things normally cost anyway??? I decided to try it on the stock 16" rims and see how it went. I trimmed the air dam back at an angle at the front of the front wheel wells. The tires fit on with no issues except for some rub at lock. I am going to pick up some rims with better offset afer I drive it for a few weeks and see how it rides... My frist impression after a quick spin was it's gonna be fine but parking in a tight spot is going to be a beotch. I will check the mileage after a tank and a week with the GPS and see what effect they have on that end. The 285's caused a solid 10% error on the speedo and odometer. So 60 MPH indicated was actually 66 etc... I imagine this will put it closer to 15-20% error, they are huge compared to the 285's. I will post some pics later all I have right now is my phone and I need to clean the shipping goo off of the side walls...

I am open to any comments or suggestions, do they make a speedohealer for an F150?

 

I'd suggest a set of 16x10 wheels with 4.5 inches of backspacing.
The speedometer on your 97 can be calibrated by changing out a plastic gear on the transmission.

 

Is they speedo gear easy to access or do I need a tranny shop to do this? and how do you figure the corrected teeth count?

I wanted to get some black steel rims (so I can repaint them if I muck them up) like A/R 767's but those only come in 16x8 with 4" backspacing. I wanted 10" rims... I need to poke around some more maybe Rock Crawler or somebody else... They make the damn 15's in 10" why not the 16's?

Thanx

And I didn't rule out the body lift but it looks like I don't need it unless I go wheeling where it will articulate the suspension...

 

I get way more drift on the highway with these and the ride is a bit more harsh. The tires do not seem to make any more noise than the BFG AT's I had on there...