Biggest tires on my 72, K-20? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**Daubs** · 08-25-2005, 08:13 PM

She's running 265's right now and looking like 285's will fit with no problem (16" rims). How much larger can I go without getting in to a lift or any body mods (cutting sheet metal)?

**hilljob26** · 08-25-2005, 08:38 PM

You Might Be Able To Fit A 305/70r16,they Are About The Same As 33's And They Usually Fit

Sooner1970_K10 · 08-25-2005, 08:56 PM

Quote:

Originally Posted by Daubs

She's running 265's right now and looking like 285's will fit with no problem (16" rims). How much larger can I go without getting in to a lift or any body mods (cutting sheet metal)?

I was able to put 33 x 12.50 x 15 with 8 inch rims on my 1970 k10

**JIMs70GMC** · 08-25-2005, 09:30 PM

I'd agree what hurts is the width of the rim. If you can stay with an 7-8" rim you should have no problems with a 33" tire. meaning a 33-9.5 on 7" rim or as wide as a 33-12.5 on an 8" wide rim.

al's71gmc · 08-26-2005, 02:47 AM

I wouldn't put the 305/70/16's (same as a 33/12.50/16), on without a lift unless you don't plan on doing much wheeling. You won't have much clearance when turning and if you hit much of a bump at the same time they will hit the wheel wells. My .02
Al

**special-K** · 08-26-2005, 07:57 AM

I have 285/75 Swampers on 8" rims on a truck that sits up a bit.Either add-a-leafs or spring shop job.These tires are nubby on the side and they`ll rub (no damage) a bit in certain turns like going into an uphill driveway.But,the shocks are way past shot.They are just things with bolts at each end.I have a lift/shocks to go on it.

earl87gta · 08-26-2005, 12:25 PM

I would get a set of ord zero rates they will give you 1in of lift and then run the 33 12.50. if they still end up a little to big never know how much your springs have sedled you can get exstended spring shackles for the front that will give you a little more lift and use an air shock in the rear or mabe a helper spring.

72 Cheyenne K20 · 08-26-2005, 03:58 PM

I've been looking for the same answer. I have a 72 Cheyenne 3/4 ton 4x4 that has 305/70/16's on it now, but has a 4" lift right now, I hope it won't rub when I take the lift out, I think the 3/4 spring will keep it high enough. I also have a 72 CST Blazer that I just got factory rally's for (15x8's). I think I'm going to run 32/11.50's on them. I shouldn't have to worry about rubbing.

Scott

08-25-2005, 08:13 PM	#1
Daubs Registered User Join Date: Jan 2005 Location: Eastern Nebraska Posts: 613	Biggest tires on my 72, K-20? She's running 265's right now and looking like 285's will fit with no problem (16" rims). How much larger can I go without getting in to a lift or any body mods (cutting sheet metal)? __________________ '72 Chevy K-20 Crate 350, SM465, 4.10's

08-25-2005, 08:38 PM	#2
hilljob26 Registered User Join Date: Dec 2004 Location: Gypsum Kansas 67448 Posts: 1,681	You Might Be Able To Fit A 305/70r16,they Are About The Same As 33's And They Usually Fit __________________ 21 2500hd duramax 58 apache HILLJOB GRAPHIX--for all your graphic needs My build thread http://67-72chevytrucks.com/vboard/s...d.php?t=542497 LS ENGINE SWAP INFORMATION THREAD http://67-72chevytrucks.com/vboard/s...d.php?t=377348 4l60 to an NP205 http://67-72chevytrucks.com/vboard/s...43#post3697343

08-25-2005, 09:30 PM	#4
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	I'd agree what hurts is the width of the rim. If you can stay with an 7-8" rim you should have no problems with a 33" tire. meaning a 33-9.5 on 7" rim or as wide as a 33-12.5 on an 8" wide rim. __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm Last edited by JIMs70GMC; 08-25-2005 at 09:32 PM.

08-26-2005, 02:47 AM	#5
al's71gmc 4 eyed fever Join Date: Jul 2005 Location: Eureka, Nevada Posts: 500	I wouldn't put the 305/70/16's (same as a 33/12.50/16), on without a lift unless you don't plan on doing much wheeling. You won't have much clearance when turning and if you hit much of a bump at the same time they will hit the wheel wells. My .02 Al __________________ 1971 GMC 2500 4x4 1972 GMC Sierra Grande 1/2 t 4x4-#1 son's truck. Recently completed resto. 4 YO daughter," Daddy, I like your truck better than Mom's." (2000 F350-ranch truck) Smart kid!!

08-26-2005, 07:57 AM	#6
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,851	I have 285/75 Swampers on 8" rims on a truck that sits up a bit.Either add-a-leafs or spring shop job.These tires are nubby on the side and they`ll rub (no damage) a bit in certain turns like going into an uphill driveway.But,the shocks are way past shot.They are just things with bolts at each end.I have a lift/shocks to go on it. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

08-26-2005, 12:25 PM	#7
earl87gta Senior Member Join Date: Dec 2003 Location: Kingsport TN Posts: 4,641	I would get a set of ord zero rates they will give you 1in of lift and then run the 33 12.50. if they still end up a little to big never know how much your springs have sedled you can get exstended spring shackles for the front that will give you a little more lift and use an air shock in the rear or mabe a helper spring. __________________ Earl 68 2500 4x4 GMC Burb

08-26-2005, 03:58 PM	#8
72 Cheyenne K20 Registered User Join Date: Feb 2003 Location: Staunton, Virginia Posts: 554	I've been looking for the same answer. I have a 72 Cheyenne 3/4 ton 4x4 that has 305/70/16's on it now, but has a 4" lift right now, I hope it won't rub when I take the lift out, I think the 3/4 spring will keep it high enough. I also have a 72 CST Blazer that I just got factory rally's for (15x8's). I think I'm going to run 32/11.50's on them. I shouldn't have to worry about rubbing. Scott

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.