What is the factory tire size for my 69 GMC - The 1947 - Present Chevrolet & GMC Truck Message Board Network

69 GMC LWB Pickup · 02-16-2011, 08:37 AM

I have a 1969 GMC 1/2 ton truck 2 wheel drive. I want to get new wheels and tires and don't know what the factory size is. The truck has two different sizes on it now and i don't know which one to use. It has a 235/75/15 and a 235/70/15. That is almost a full inch difference in the overall diameter. Can anyone tell me what the factory size is supposed to be so i can choose the right wheel and tire. This is important because i want the speedo to be as accurate as possible. Thank you to anyone that responds.

**special-K** · 02-16-2011, 09:13 AM

There never were radials or metric sizes offered on these rucks,so you have to go with the closest radial/metric. There were also various options from factory in the bias ply. The 75 series is the closest match to the original 78-series profile,so I like the 235/75s best. The standard size was a bit smaller,like 225/75s.

02-16-2011, 08:37 AM	#1
69 GMC LWB Pickup Registered User Join Date: Oct 2010 Location: Tallahassee, Florida Posts: 3	What is the factory tire size for my 69 GMC I have a 1969 GMC 1/2 ton truck 2 wheel drive. I want to get new wheels and tires and don't know what the factory size is. The truck has two different sizes on it now and i don't know which one to use. It has a 235/75/15 and a 235/70/15. That is almost a full inch difference in the overall diameter. Can anyone tell me what the factory size is supposed to be so i can choose the right wheel and tire. This is important because i want the speedo to be as accurate as possible. Thank you to anyone that responds.

02-16-2011, 09:13 AM	#2
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,851	Re: What is the factory tire size for my 69 GMC There never were radials or metric sizes offered on these rucks,so you have to go with the closest radial/metric. There were also various options from factory in the bias ply. The 75 series is the closest match to the original 78-series profile,so I like the 235/75s best. The standard size was a bit smaller,like 225/75s. __________________ "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 ~



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