tire size? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

1971C10Blown · 01-15-2015, 12:10 AM

what is the biggest size tire you can fit on a stock suspension truck with stock box. front and back. can you fit a 305on the back and a 275 on the front? also how tall. I'm using an 18" wheel no backspacing yet. also truck has leafs.

Mike C · 01-15-2015, 09:23 AM

My truck is a stepside, so if yours is a fleet you can probably get away with a bigger tire. Rim diameter doesn't have a whole lot to do with fitment. Section width and overall height do.

I have 275 55 17 on the rear on a 17x9 wheel with 5" backspacing. This is pretty much as big a tire as you can get on a step without inner bedside mods or lip rolling. I have a DJM flip that lowers the truck about 7".

On my truck I went with a narrower tire on the front because that's the look I wanted. 235 55 17 on 17x8 with 4.5" backspacing.

I swapped in a wider '72 rear axle. If your truck is a 71 like your screen name you have the wider rear. If it's a 70 like your signature it's probably the wider but no guarantee. That affects backspacing tremendously.

OKGMC4 · 01-15-2015, 12:11 PM

I am curious about this as well. I have a 4.5/6 drop and would like to run 10" rims all the way around with 305/35r20 tires. I just don't know how far the stock inner fenders can be pushed. Everyone seems to have skinny tires on the front, or the pro touring trucks I've seen run big tires up front with no inner fenders at all.

1971C10Blown · 01-15-2015, 08:25 PM

Quote:

Originally Posted by Mike C

My truck is a stepside, so if yours is a fleet you can probably get away with a bigger tire. Rim diameter doesn't have a whole lot to do with fitment. Section width and overall height do.

I have 275 55 17 on the rear on a 17x9 wheel with 5" backspacing. This is pretty much as big a tire as you can get on a step without inner bedside mods or lip rolling. I have a DJM flip that lowers the truck about 7".

On my truck I went with a narrower tire on the front because that's the look I wanted. 235 55 17 on 17x8 with 4.5" backspacing.

I swapped in a wider '72 rear axle. If your truck is a 71 like your screen name you have the wider rear. If it's a 70 like your signature it's probably the wider but no guarantee. That affects backspacing tremendously.

i really like that truck

Mike C · 01-15-2015, 08:43 PM

Thanks! I've had it for almost 15 years and it's been lowered for 5 days! Been fun driving it around this week.

01-15-2015, 12:10 AM	#1
1971C10Blown Registered User Join Date: Aug 2010 Location: athabasca alberta Posts: 106	tire size? what is the biggest size tire you can fit on a stock suspension truck with stock box. front and back. can you fit a 305on the back and a 275 on the front? also how tall. I'm using an 18" wheel no backspacing yet. also truck has leafs. __________________ Jared 2014 Ram 2500 powerwagon 2006 GSXR 600 2012 Arcticcat proclimb 800 1970 C10 SWB 5.3LS turbo and 4L60E "all throttle no bottle" "Nitrous is like a hot chick with an STD, you wana hit it but afraid of the consequences" "its not turbo lag, its for play"

01-15-2015, 09:23 AM	#2
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,709	Re: tire size? My truck is a stepside, so if yours is a fleet you can probably get away with a bigger tire. Rim diameter doesn't have a whole lot to do with fitment. Section width and overall height do. I have 275 55 17 on the rear on a 17x9 wheel with 5" backspacing. This is pretty much as big a tire as you can get on a step without inner bedside mods or lip rolling. I have a DJM flip that lowers the truck about 7". On my truck I went with a narrower tire on the front because that's the look I wanted. 235 55 17 on 17x8 with 4.5" backspacing. I swapped in a wider '72 rear axle. If your truck is a 71 like your screen name you have the wider rear. If it's a 70 like your signature it's probably the wider but no guarantee. That affects backspacing tremendously. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

01-15-2015, 12:11 PM	#3
OKGMC4 Registered User Join Date: Oct 2009 Location: Broken Arrow, OK Posts: 1,218	Re: tire size? I am curious about this as well. I have a 4.5/6 drop and would like to run 10" rims all the way around with 305/35r20 tires. I just don't know how far the stock inner fenders can be pushed. Everyone seems to have skinny tires on the front, or the pro touring trucks I've seen run big tires up front with no inner fenders at all. __________________ 56 GMC BUILD THREAD: http://67-72chevytrucks.com/vboard/s...d.php?t=368649 69 long bed Chevy turned 67 gmc jimmy roadster: https://67-72chevytrucks.com/vboard/...d.php?t=851167

01-15-2015, 08:43 PM	#5
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,709	Re: tire size? Thanks! I've had it for almost 15 years and it's been lowered for 5 days! Been fun driving it around this week. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax



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