Tire fit question

[RenoHuskerDu]

I have a set of new  tires kicking around, and I wonder if 315/75r16 tires would fit on a 1986 F250 4x4?  It came with  barely worn BFG 33x12.5" tires on it that are 14 years old and therefore unsafe.  

I'm guessing that the 315/75r16s are too tall, nearly 35" if my calcs are correct.  My son ran 35s on his OBS with  no lift but it's a solid axle F350, and the 86 F250 is TTB suspension.

The aftermarket wheels on this Bullnose measure 9.5" across the inside of the bead surfaces. Wide!

[Gary Lewis]

I think you'll be fine.  I'm running 285/75R16's on Big Blue and even when it was on TTB's there was no problem.

The biggest question is in the offset, and while I don't remember what my wheels have in offset I can find out.  But the tires are in what looks to be the same position as those in your picture, meaning sticking out from under the truck a bit.

[Gary Lewis]

Oh, wait!  The wheels on the truck aren't the wide ones.  Which are you planning to use?

[Rusty_S85]

33`s will require at least a leveling kit as I have seen stated before.  31s dont need a leveling kit but would be nice to have it if you are going slightly wider on the tires like I did on my '82.

Currently I am running KO2`s 31x10.50-15 on mine with no issues, the more aggressive shoulders of the KO2s over the KO1s result in scrubbing the I beam trailing arm which I am currently drawing a blank on the correct term for.

I dont think you could run 33s or larger on 2wd or 4wd without some kind of leveling kit or lift kit.

[Gary Lewis]

Rusty - Don't miss that he has an F250, not a 150.

[RenoHuskerDu]

Well spotted. That white one on the deck is the one I measured at 9.5" between the bead walls.

The chrome wheels on the truck don't seem to be quite as wide, but I'd bet they're over 8" wide. We need to pull off those tires and get some decent rubber before we drive him anywhere but in our field or dirt road. I put in 30psi and stood way clear in case one blew.

[Rusty_S85]

Gary Lewis wrote

Rusty - Don't miss that he has an F250, not a 150.

I think it applies to F250s as well that you need a leveling kit or a lift kit for 33" or taller tires.

[Gary Lewis]

Big Blue was effectively stock when I got him and he handled the 285/75R16's, which are 33" tires, just fine.  No leveling nor lift kit, and no tire rubbing.

[Rusty_S85]

Gary Lewis wrote

Big Blue was effectively stock when I got him and he handled the 285/75R16's, which are 33" tires, just fine.  No leveling nor lift kit, and no tire rubbing.

Interesting, way how leveling/lift kits talk even for the F250s the kits make it sound like its a requirement for taller tires.

[ArdWrknTrk]

Gary Lewis wrote

Big Blue was effectively stock when I got him...

Um.....no
Not at all was Big Blue anywhere close to stock.

And since these 250's came with a maximum 7" rim width I'm not even sure you you could begin to compare with whatever backset/offset his rims have.

You're definitely going to need to start trimming fenders and adding lift when you get above 285.
The 250 has an advantage there, because it only has an inch of suspension in front (stock)

[Gary Lewis]

The suspension was stock, other than having Bilsteins. But the wheels weren't. And the 285's didn't come anywhere near rubbing with the stock suspension.

So Reno will be fine with the right wheels. In fact, the wheels that are on his truck put the tires at probably the same place those on Big Blue are, so he should be fine with them. But with the white wheels he will have to determine backspacing and do some math.

Here's a comparison, and that's a pic of Big Blue before the transformation with the D60.

[351FUN]

Rusty_S85 wrote

I think it applies to F250s as well that you need a leveling kit or a lift
kit for 33" or taller tires.

Absolutely not.  With the right offset wheels 35's fit fine with no rub.  I ran 285/75 on the stock wheels for years with no rub at all.  Now it's on 37/12.50R16.5 with factory suspension and cutout flares.