Ok so I've done a bunch of research and I think I am on the right track but I wanted some knowledgable opinions before I spent much money.....

I have an 08 FX4 SCREW and I just bought a 2" leveling kit that I plan on installing this week. I plan on buying some 20's and some 35x12.5 MT ATZ's. There are a few different styles I like but the final selection boils down to what will work best for clearance as each style has a different backspacing. I believe that the best width to go with is an 8.5" and the best backspacing to go with is as close to stock as possible. I found some wheels that I really like in the Granite Alloy GA4.6 (Machined w/ black accents). They are 20x8.5 and have a backspacing of 6.10". I've read a few different posts and believe that stock 20's have a backspacing of 6" even though some people say 5.5". You think this set-up is going to work with minor or no clearance problems?

I've heard a small rumbling of tires rubbing on suspension and stearing components at full lock and I want to avoid that if possible. I've also read a few posts that say that 2" or 2 1/2" leveling kit and 35x12.5x20's with almost 6" of back spacing produce no clearance problems at all.

Any advice and knowledge you all can give me will be greatly appreciated!

 

It's an unusual width/bs combo but it may work. I'm pretty sure you will have some rubbing. Personally, I'd go with a 305/55-20 (33x12.50) tire.

 

Hey thanks for the reply wandell. I'm really intent on going with 35's but I am flexible about the wheel type. What backspacing do you think would work best? Any knowledge of what width and backspacing others are using to fit 35x20's on their leveled 04-08's?

 

I forgot to mention that I am willing to go with a small body lift too in order to fit the 35's and possibly just for asthetics. I really really don't want to spend the money involved in a full suspension lift and think that most of the ones I've seen aren't the desired look I want.

 

they only make 3in body lifts for 04-08

 

WIth a body lift, you can use about any wheel to fit 35's, but a 9 inch wheel with 5 inches of bs is most common. If you don't add the body lift, I'd suggest an 8 inch wide wheel with 5.5 inches of bs.

 

Hey guys thanks again for the info. I think I finally figured this thing out. see if you follow me on this one.....

The stock 18x7.5's I have on my truck now have a bs of 5.5" and are fully capable of running 35x12.5's on them with a small amount of rub at full **** on the a-arms.....

The stock Ford F150 20" wheels are 8.5" wide and have a bs of 6". I've read enough posts from people that have done it to believe that you can mount 35x12.5's on them with the same minor rub on the a-arms....

Both combo's wind up being the same width of tire overall with the same amount of clearance on the truck side. Even though the 20x8.5" has a .5" deeper bs, the width is a full inch wider than the 18x7.5" so it distributes the distance between the inside of the wheel and the outside. The tire ends up being mounted in the same position either way.

The wheel I've chosen is 20x8.5" and has a bs of 6.10". That's the same dimension as the oem 20's but with .10" more bs. I am going to counter that additional bs with a .25" spacer to make the final bs 5.85" and hopefully get rid of the full **** a-arm rub all together.

Does all that make sense and if not why?

Thank you again!

 

Yep, makes sense. I'd try to avoid using the spacer if you can. The new F-150's are really sensitive and prone to vibration issues. If you choose a tire with large sidewall lugs, like the Mud Grappler, you will have more rubbing issues than with a tire with a normal style sidewall.

 

I've done a lot of thinking and calculations in the past few days and I think I've come up with a better combination and solution....along with annoying the crap out of girlfriend by ignoring her so much.....can't be perfect....a man's gotta have priorities!

I figured out a bunch of small details having to do with backspacing and tire size in relation to the stock set-up and the changes involved in adding a specific size tire width, backspacing and wheel width.

I've decided to go with the XD Spy wheel(black and machine finish) in 20x8.5". It has a backspace measurement of 5.46".

This wheel with 35x12.5" ATZ's will give me 0.2" of additional tire on the truck side and 1.3" of additional tire on the the outward side.

I'm 99.9% positive I won't have any rubbing issues on the a arms or frame but I might have a small issue with rubbing on the back of the front wheel well liner and the lower front valance. If That's the case a very small amount of trimming will cure the problem with both. I figured I would be happier doing the small amount of trimming if I have to than I would be if I had to deal with limiting my turn radius or dealing with the frustration of tire rub on the truck side of the wheels.

I'll be sure to post an update when I finally do purchase these wheels and tires so that everyone will know how it works out for their future clearance needs. Along with pictres of course!

Anybody see any problems with this set-up before I do make the purchase?

Also, The leveling kit I bought has 1 1/2" spacers but I was told it would lift the front 2"- 2 1/2". Can anybody attest to that? It sounds right but I'd like another opinion or two before I put it on.

Thanks again guys! I can't wait to get this stuff on my truck and make it 'mine'!

Anybody want to buy a set of OEM chrome step bars off of my 08 Screw?

 

It's gonna be tight, but they may fit without rubbing.