Dually Tires - How Big? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Tance · 01-08-2010, 04:07 PM

I’m restoring a 1984 K30 one ton (ex-military M1028A3 dually). It had Buckshot 305/70R16s (33s) when I bought it, they look like one huge tire in the back because there’s no gap between them… I know, everyone says bad news… rubbing, heat, blowout, etc. But they must be a pefect fit because after disassembly there’s not so much as a smudge on the sidewalls… and I was goosnecking a 30 ft 5th wheel so they were loaded.

Anyway I’d like to go with bigger tires, probably 35s or 37s. So my question is… what’s the biggest tire size I can run on a dually? I’m guessing the answer is as big as I want, as long as I use a spacer to keep them apart.

So assuming I get fender clearance with a lift, then dually tire size would be limited by wheel width… up to 35s on a stock 6-7” rim, 37s (and up) on a 10’ rim… correct?

As for width... 12” wide no spacer… 12.5” or wider, need spacer, correct?

Thanks!

LONGHAIR · 01-08-2010, 05:32 PM

You may run into a gear ratio issue with a tire that big, especailly if you do a lot of towing.

Prerunner1982 · 01-08-2010, 06:15 PM

It should have 4.56 gears already...but with tires that size aren't the optimum for towing.

74 C-30 · 01-08-2010, 11:53 PM

i hear 9.00-16 are a good size. I personally have 235/75r16, which are like 32" tall

andrewmp6 · 01-09-2010, 07:39 AM

Or if you really want big tires the semi wheels can do it but are pricey.

72freak · 01-09-2010, 07:49 AM

Quote:

Originally Posted by 74 C-30

i hear 9.00-16 are a good size. I personally have 235/75r16, which are like 32" tall

Agreed.........9.00, 225's, 215-85, 235-85 all wor and look correct

Robert1970C20rstbukt · 01-09-2010, 11:11 PM

Check out this badass off-road tow truck it has 37's with tubes on the stock rims with spacers, watch the video at 2:53 the axle hub is flush with the outer wheel flange

I run 235/85's on my flatbed dually and they're just right, about an inch between the sidewalls when loaded with the right pressure. The truck originally had 7.50-16's with tubes, kinda strange considering the rims are solid 16's. Factory sizes back then in the '84 manual were 7.50-16, 215/85/16, and 235/85/16.

YouTube- BROKE STUCK & ****ED RECOVERY TEAM...

sickshortbed84 · 01-13-2010, 10:17 PM

i run 38.5x11 super swamper boggers accross the back of my crew cab dually with a 2 inch spacer between the stock wheels. no rubbing and looks sick!

01-08-2010, 04:07 PM	#1
Tance Registered User Join Date: Mar 2006 Location: Baytown, Texas Posts: 4	Dually Tires - How Big? I’m restoring a 1984 K30 one ton (ex-military M1028A3 dually). It had Buckshot 305/70R16s (33s) when I bought it, they look like one huge tire in the back because there’s no gap between them… I know, everyone says bad news… rubbing, heat, blowout, etc. But they must be a pefect fit because after disassembly there’s not so much as a smudge on the sidewalls… and I was goosnecking a 30 ft 5th wheel so they were loaded. Anyway I’d like to go with bigger tires, probably 35s or 37s. So my question is… what’s the biggest tire size I can run on a dually? I’m guessing the answer is as big as I want, as long as I use a spacer to keep them apart. So assuming I get fender clearance with a lift, then dually tire size would be limited by wheel width… up to 35s on a stock 6-7” rim, 37s (and up) on a 10’ rim… correct? As for width... 12” wide no spacer… 12.5” or wider, need spacer, correct? Thanks!

01-08-2010, 06:15 PM	#3
Prerunner1982 Registered User Join Date: Oct 2002 Location: Edmond, OK Posts: 5,904	Re: Dually Tires - How Big? It should have 4.56 gears already...but with tires that size aren't the optimum for towing. __________________ Jon 1982 Chevy Silverado 350/th350.... RETIRED 1993 Jeep XJ 2 door(Cherokee) 4wd 4.0ltr/AX-15 (5spd)/NP231 .... Oklahoma Roll Call Last edited by Prerunner1982; 01-08-2010 at 06:16 PM.

01-08-2010, 11:53 PM	#4
74 C-30 Dually Pride Join Date: Jun 2008 Location: NH Posts: 540	Re: Dually Tires - How Big? i hear 9.00-16 are a good size. I personally have 235/75r16, which are like 32" tall __________________ If I have to explain, you wouldn't understand. '74 Chevy C-30 350/4 speed/dually '94 Ford Ranger

01-09-2010, 07:39 AM	#5
andrewmp6 Registered User Join Date: Jan 2009 Location: Louisville,Ky Posts: 5,811	Re: Dually Tires - How Big? Or if you really want big tires the semi wheels can do it but are pricey.

01-13-2010, 10:17 PM	#8
sickshortbed84 Registered User Join Date: Feb 2007 Location: Connecticut Posts: 58	Re: Dually Tires - How Big? i run 38.5x11 super swamper boggers accross the back of my crew cab dually with a 2 inch spacer between the stock wheels. no rubbing and looks sick! __________________ the fleet..... 57' shortbed stepside 4x4 72' longbed cheyenne super 4x4 78' blazer lil lift w/ chalet 84' shortbed lowrider aka "troubletruck" 84' 1 ton crew cab dually lifted 8" on 38.5 boggers 87' burb shes my daily 89' blazer, wheelin/plow rig 8?' blazer chassised super short stepside

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