The Stovebolt Site Forums The Shop Area Engine Shop 31x10.5 R15 on a '50 GMC 3/4t

The old girl needs some new bots. I'm looking at fitting some bigger tyres to gain a bit of cruising speed, and to keep her bum out the snow.

Can anyone tell me if 31x10.5R15 will fit without clearance issues.

Truck is totally stock longbed.

Many thanks

doh!

Don't know why I posted this in here, can a mod either delete it or move it please.

Thanks

With the right wheels, that tire should clear fine. However, you may run into issues finding the proper wheel to work with that size tire in an 8 lug pattern. A 31x10.50x15 tire will require a 7" wide wheel at the minimum, 8" would be preferred. Finding a wheel that size in 6 lug is fairly easy, as GM used them on 1/2 ton 4x4s for many years. But in an 8 lug, you would have to look for aftermarket or custom made wheels.
You also make mention of being able to drive in snow, without having 4wd, a wide floatation tire like the 31x10.50 isn't the best choice. A tall, narrow tire would perform much better. I would suggest looking into a 16x7 wheel, with 3 to 3.5 inch backspacing, and using a 215/85/16 or 235/85/16 tire. Either will help with the rad speed issue, and will also give you the snow performance.

Thanks for the advise.

Not sure a rim width I've got the spare in the workshop at the moment, just trying to get the split rim off.. lol (grumble)

Because of the weather we get in the UK, you can have 1-4" of snow through the day, for it the almost melt and then freeze before daybreak. For more snow the fall. Narrow tyres tend to cut through to the ice underneath and you end up going nowhere.

There was a guy here in town, where I live, that had 31/10.50/15's on a 54 3/4 ton truck. They were mounted on wagon wheel rims. Seemed to drive fine. Like Longbox stated, You'll need rims that don't have alot of backspace. 4" of backspace is about the limit of getting anything to fit on these old trucks.

I've also worked on a 2wd Apache for a guy that had 31/10.50's. I was surprised how easy it steered and drove. I'm sure it would've been a different story if it were loaded.

I have 31x10.5 R15's on mine, but it's a custom application. Mine are on 10" wheels though, you'll want to use somewhere in the range of an 8" to 10" wheel. With an 8" wheel if you find proper backspaced wheels they should fit mostly within the wheelwells. For improving traction, also use sand bags and pay close attention to your choice of tire for the terrain conditions you anticipate.