1970 GMC questions

[4tiresngas]

Welcome to the board from Southern California. That is a nice truck! I keep telling my wife once my '69 SWB Stepside is right, I'd drive it everyday. She says I'm crazy. I think the $500+/month payment on my 04 Dodge Ram Quad Cab is what's crazy...and the HEMI only gets 13 MPG.

[Old Yeller 1970]

Originally Posted by jlmerie

Old Yeller 1970, I have to admit I have always been perplexed by tire sizes. I currently have P235 70 R 15 and these look tiny in the wheel wells. The truck feel like it sits too low also. I would like to get a taller tire that would help offset the steep gear (411) in the back. I have a set of later model chevy six lug wheels from a suburban. They have 31 inch tires on them. I think I am going to throw them on and see how they look and how it drives. They might be the answer.

The average 235/70R15 tire is 28" tall.
By changing to the 31" tires your effctive gear ratio will be 3.71:1.

I think 67-72 trucks generally came with 235/75R15 tires which are 29" tall. That would explain why yours look a little short to the eye.