How tall of tire can I fit without a lift?

[bike-maker]

I've got 35's on no lift. I added an extra leaf to each of the front spring packs, so it might just sit 1" or so higher than stock. Also resulted in having the ride characteristics of a skateboard - front suspension doesn't move much. That having been said, never had any clearance issues, even loaded heavy on uneven terrain. Plenty of clearance on the leafs, the close spot is the inner fender - and it'll bend out of the way if it has to.
Most people will tell you 35's won't fit. But they somehow work just fine on mine. I think the biggest hurdle is having the right wheel width and backspacing.

 

[Fordman84]

One of my friends had a bone stock 87 F-250 6.9, and he managed to stuff 37 inch millatary tires under it, only had rubbing at full luck, and he was using plane jane steel 16.5's. And he regulary had the bed full of wood for his house.

 

[PwrSmoke]

235/85R-16 were the stock 4x4 tire and with said tires, the speeds on many trucks (at least in the Bullnose era) reads ~10% more than actual. Ditto the odo. Among other things, it fools you into thinking you are getting better MPG than you really are.

285/70R-16 (roughly a 33+) fits on my truck on 8.5x16 alloy wheels (backspace is a little less than stock but I don't recall the exact spec). No rubbing and my front spring are even a little saggy. From what I've seen a 285-70 or a 33x12.50 is a pretty safe fit, depending on what wheel you install them on.

I would caution against installing a 33x12.50 or 285/70 on the stock 6.5-in. wheels. Putting a tire designed for a minimum 7.5-in. rim (that's the minimum for many 33-ish tires) on a 6.5-in. rim will make the mounted section width dimension of the tire narrower by about 1/2-in (each 1/2-in. on the rim equals 1/4-on the section width) but the tire will not perform optimally (or adequately IMO) when mounted on a rim below the minimum rated rim width. Tends to make the tread more rounded and you lose braking and cornering grip. Tire is more vulnerable to being tolled off the rim with a lot of side fore also.

 

[franklin2]

I've got 35's on no lift. I added an extra leaf to each of the front spring packs, so it might just sit 1" or so higher than stock. Also resulted in having the ride characteristics of a skateboard - front suspension doesn't move much. That having been said, never had any clearance issues, even loaded heavy on uneven terrain. Plenty of clearance on the leafs, the close spot is the inner fender - and it'll bend out of the way if it has to.
Most people will tell you 35's won't fit. But they somehow work just fine on mine. I think the biggest hurdle is having the right wheel width and backspacing.

I am going to flame you a little bit. You DID lift the suspension some, along with admitting the suspension doesn't move as much also. Your truck does not have the stock suspension with 35's. And you didn't say anything about the firewood test. That's important to me, that's all I use for heat in the winter time.

But, if someone does want to run 35's, your formula is a good one to follow. You might want to tell us how it does with a large load in the bed if you have tried it.

 

[chris142]

Im not seeing inch size tires in 16 or 16.5 around here any more. All metric numbers. Im running 286\75\16s on 6 inch wide stock wheels until last week when i went to 7 inch wheels. Nobody would mount my new tires on my 6 inch wheels

 

[PwrSmoke]

Im not seeing inch size tires in 16 or 16.5 around here any more. All metric numbers. Im running 286\75\16s on 6 inch wide stock wheels until last week when i went to 7 inch wheels. Nobody would mount my new tires on my 6 inch wheels

What 7-inch wheels did you use? I just found 4 early '90s Ford 7-inchers that look just like the OE wheels and will carry the hubcaps. I will be fitting those wheels as I have time and selling the alloys. Will probably go to a slight skinner but equally tall tire.

 

[chris142]

Mine came off an 01 e350 church van in picapart and the stock dog dish caps fit.

 

[opusd2]

My truck is stock and has 305/70-R16s on it. No rubbing... Plus the person who had it before me (or the person before them) changed the speedo in the transfer case gears so the speedometer would read correctly.

I'd like to go with 35s. There seems to be room for them and without a lift kit.

 

[bike-maker]

I'm not sure where my truck sits height wise.
One side was sitting on the bump stop, the other side only had about 1/8".
With the suspension in this configuration, I had 33's on the truck with plenty of clearance everywhere.
I had a spare TTB front end laying around, so I took just the stock upper leafs off of it, cut about 8" off of the ends, and threw them in my spring pack.
My guess is that it lifted it about the same amount as an add-a-leaf would. But I really don't know.

Took a measurement from the middle of the hubs up to the top of the wheel opening lip; Looks to be right at 22-3/4" if anyone cares to compare.

 

[chris142]

My speedo and odo were reading faster than i was going with the 235 tires. Its now 1 mph fast with 285's .65 mph on the speedo is really 64 mph actual.