Tire size
Thread Starter
Drifting
Joined: Nov 2013
Posts: 1,547
Likes: 282
From: Scottsdale Arizona
Tire size
I'm getting ready to buy new tires for my 77 and I'm also replacing the alloy wheels with 15X8 rallye wheels that have the 4" backspace. Currently, I have 225 70 R 15 on the rear. I'd like to change to a wider tire and probably won't go larger than 235 70 R 15. Just want to make sure that I won't have any clearance issues. Any opinions or advice will be appreciated.
Race Director
Joined: Oct 2000
Posts: 12,679
Likes: 3,131
From: Shamong, NJ
The OEM tire on your car was a GR70x15, and the modern equivalent to it is the P225/70R15, that your currently running. A P235/70, really won't be noticeably wider, but it will be over a half inch taller.
I agree with gwank, that if you really want to go with a wider tire, look at a P255/60R15. This was the optional size tire offered by Chevrolet, on 78-82 Corvettes. It is significantly wider, than the P225/70, but will be the same height as the P225/70, so it won't effect the accuracy of your speedometer. The P255/60, can be used on the front of your 77 also, but it may require the trimming of the forward edge of the front wheel opening lip, slightly.
I agree with gwank, that if you really want to go with a wider tire, look at a P255/60R15. This was the optional size tire offered by Chevrolet, on 78-82 Corvettes. It is significantly wider, than the P225/70, but will be the same height as the P225/70, so it won't effect the accuracy of your speedometer. The P255/60, can be used on the front of your 77 also, but it may require the trimming of the forward edge of the front wheel opening lip, slightly.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
If you go with a 70 series tire, 215-225 will give you close to the correct outside diameter. If you go with a 60 series tire, 245-255 will be approx. the right O.D size. Personally, I like the look of a 60 series tire on the C3.
