tire size on 3/4-ton and srw 1-ton trucks

[kipps]

Was a 235/85r16 the standard size during the squarebody era? Were any taller tires fitted? Has anyone found any other tall & skinny tire sizes that look good on these heavier trucks and are easily available?

I have 16x10 rims and 305/70r16(33x12.5) tires on my truck right now. Once I get it back on the road, I want something a little more fuel mileage friendly. I also want to go to a stock tall-and-skinny look, instead of the fat mud tire look that I have right now. I don't mind going a little taller than stock as long as I can keep the width within check.

[mongocanfly]

I'm running bfg 255/85-16 on 2 trucks....conversion says its 33.1x10R16
But they're not exactly that tall..more in the 32in range
love the tall skinny look

[kwmech]

I saw a dually couple years ago that was up for sale by the original owner and they were bragging that they just put brand new tires on.............215/75r-16s, yup 215s they looked so small on that truck. I passed on the truck, I figured the rest of truck was probably the same amount of stupid to it. That 454 was probably screaming down the road and sucking the fuel as fast as it could. I had Cooper 255/85s on my wrecker. that was a good fit and looked nice. Tires on the rear had about 1/2'' in between them at the bottom buldge

[THI]

in the 1980's the Light Duty 3/4-ton got 215/85-R16's and the Heavy Duty 3/4-tons and 1-tons got 235/85-R16's. Dually's came with the 215/85-R16's.

In the 1970's it was either 7.50x16 or 9.50x 16.5 - I could be wrong on the 16 inch size, any 3/4-ton from the 1970's that I have owned came with the optional 9.50x16.5's

[kwmech]

Originally Posted by THI

in the 1980's the Light Duty 3/4-ton got 215/85-R16's and the Heavy Duty 3/4-tons and 1-tons got 235/85-R16's. Dually's came with the 215/85-R16's.

They looked like toy tires on that crew dually. Can't believe GM did that OE. Those 215s are what-- 29-30'' tall

[kipps]

Originally Posted by mongocanfly

I'm running bfg 255/85-16 on 2 trucks....conversion says its 33.1x10R16

I've looked at those. They're not cheap, and they're only available in aggressive tread patterns. I wish they had something halfway between a All-Season tire and a All-Terrain tire that didn't cost as much.

[DoubleDubya]

I had 7.50-16's on my '76 3/4 ton Chevy. I think it was a 7800 GVW truck.

[cadillac_al]

I wouldn't use 7.50 tires on those 10" rims. I think you are stuck using 10.50 or 12.50 tires.

[kipps]

Originally Posted by cadillac_al

I wouldn't use 7.50 tires on those 10" rims. I think you are stuck using 10.50 or 12.50 tires.

I will swap out the rims when I do this. There's a decent set of stock rims and hubcaps on a k20 in a local yard. I was quoted $250 for the whole shebang, or $100 for just the hubcaps. I think I could sell my current tire/rim combo for enough to make it worth it. I'm just wondering if I'll regret buying those 16x6.5 rims, and will have preferred to go with a different set of rims instead. Either way, I'll get the hubcaps.

It looks like my only two reasonable tire options are 235/85r16 on stock 16x6.5 rims or 285/75r16 on 16x7 Econoline rims or aftermarket 16x8 rims. The second option is a bit wider than I wish, and are probably tall enough that I should add a two inch lift to the truck to maintain the proper appearance.

For the sake of price and practicality, I'll probably go with the stock rims from that junkyard k20, and install the stock 235 tires on them.

[Mike C]

265 75 16 is the same height as the 235 85 16. Can give you some more width without going taller. If you go wider AND taller can interfere with front fender depending on the tire and wheel combo. I have a C20 crew cab with the 265 75 16’s on some Alcoa singles.

I think the 235 85 works well on a dually and that is what is on my K30, but they are Super Swamper ND’s and are really aggressive looking. I have a C30 cab and chassis truck with 215 75 16 and it is MUCH lower than the K truck. It has a skirted welding bud and on it and hopefully the 235 85 fits when it time for new tires!

[MJN]

Originally Posted by kipps

Was a 235/85r16 the standard size during the squarebody era? Were any taller tires fitted? Has anyone found any other tall & skinny tire sizes that look good on these heavier trucks and are easily available?

I have 16x10 rims and 305/70r16(33x12.5) tires on my truck right now. Once I get it back on the road, I want something a little more fuel mileage friendly. I also want to go to a stock tall-and-skinny look, instead of the fat mud tire look that I have right now. I don't mind going a little taller than stock as long as I can keep the width within check.

Standard sizes can be found at the GM Heritage Site in the Vehicle Info Packets- https://www.gmheritagecenter.com/gm-...tion-kits.html
Best to find the specific year you have. For 1980, for example, standard tires on a C/20 were 8.75Rx16.5, C/30 got 9.50R-16.5D Load Range D for fronts and 9.50R-16.5 Load Range E for rears.

[kipps]

I bought five decent condition OEM 16x6.5 rims from the junkyard today, along with 4 reasonably nice hubcaps. Now I need to find a buyer for my mud-tire set so I can afford to put new tires on these rims. I should get these sandblasted and powdercoated white first, but we'll see...

[factorystock]

Originally Posted by THI

in the 1980's the Light Duty 3/4-ton got 215/85-R16's and the Heavy Duty 3/4-tons and 1-tons got 235/85-R16's. Dually's came with the 215/85-R16's.

In the 1970's it was either 7.50x16 or 9.50x 16.5 - I could be wrong on the 16 inch size, any 3/4-ton from the 1970's that I have owned came with the optional 9.50x16.5's

I agree, the industry generally abandoned the 16.5" in the early 80's and went to the 16". Up to about '75 the only 16" was the heavy duty 2 piece design. When GM stopped offering the 2 piece 16" they created a new 16" one piece for all the buyers who wanted to still run 16" tires. This 16" rim was rare in the '75-'80 era, but was a optional size then that few ordered. Probably just as rare as the 16" 5 lug that few ordered optionally.