[Musclecarpilot]

Hey gang,

Looking more likely I'll be a 65 GTO owner later this month and have a question about tires. I've been out of the Pontiac camp for a little while, and I'm really into stock looking/appearing cars. This 65 has the PHS, but I don't have it handy (I'm away on a trip and can't get to it) so don't know what wheels/tires it came with originally. Regardles, I'd like to run the Rally 1s with bias redlines since it has Cragar SS wheel on there now. I'm thinking of going with the 15" Rally 1s over the 14" ones, so what would be the biggest tire I could stuff under there without it rubbing? I assume F70s would be fine, but would G70s work too or is that too wide or tall? What bias redline are you guys running on what size rim on your 65s? No, I'm not going with radials. Just the bias plys. Thanks for the help guys!

Cheers

[64woodwheel]

This might be irrelevant to taller tires, but I have 275 40 17 on 17 x 9.5 Torq Thrust II on my 64. Tires are are about 11" wide and 25.7" tall. There is a lot of room in the back of those 64 - 65's

[Andre]

In the last 8-10 years, it has been possible to purchase radial tires that have a redline applied to them. That is what I run on my cars, and have bought them from Diamondback Radials. Coker also makes a redline radial and a redline bias ply, but unless you are looking for all the points at a AACA or similar show, I suggest a radial redline. I am running 225 70 14 which is significantly wider than stock on my '64 and '66
To me the old bias ply redline is a scary thing on a dry day, and flat out death defying on a wet metal drawbridge.

[Dick Boneske]

OEM tire size on the '65 GTO was 7.75 X 14. They had about 4" of tread on the ground.

Most all of us have gotten used to more modern cars/trucks that actually go where you steer them. From my experience with many old Pontiacs (five GTO's) with bias ply tires, I can tell you that handling, braking, traction, and ride quality are terrible with bias ply vs. radial tires. The most stark example was my '64 GTO in the mid-80's when I finally put 225/70R14's on it in place of G78X14 bias ply tires. It changed driving that car like no other change I'd ever made. The suspension in our old GTO's, however tight the ball joints, tie rod ends, steering box, and idler arm, tends to follow cracks and any uneveness in paved roads with bias ply tires.

As Andre points out, Coker or Diamondback will put a redline on any black tire, radial or bias ply. Wide Ovals sized G70X14 or 15 will fit your GTO wheelwells easily. But, if you're interested in original appearance, they don't look any more original than radials. So, why not use radials and gain the safety and ride quality bias ply tires cannot match?

Not that it matters to most old GTO owners, but bias ply tires last a maximum of about 17,000 miles. Radials often last 50,000 miles or more.

[Keith Seymore]

For many years we had 15" bias plys on our '65: an F70-15 on the front on a 15x6 Corvette rally, H70-15 on the back on a 15x7 rally.

The fronts would just "kiss" the point of the chrome trim at the rear of the wheel opening every so often. No other rubbing beyond that.

K

[Tim john]

If set on bias ply and filling the well up nicely, the G70-14 fits the bill very well. I have run G-70 - 14 Firestone Super Sports since 1975. Car is 67 GTO.

Tim john---

[Jerry H.]

Just to answer you initial question. 7.75x15 will work and look correct except for being on a 15" wheel. If you want more tread width and stay with a bias ply tire, then F70-15 will work. But at stock height specs, a G70-15 will rub.

[Musclecarpilot]

OK, so F70x14 yes, G70x14 yes, F70x15 yes, but G70x15 slight rubbing.

I have extensive experience with bias plys and have run them for years without any issues but they have been on Mopars, hence me asking about sizes that will fit on an earlier GTO. Mopar wells are huge and can take any tire you can throw under them. I had a 67 GTO, but that was a while back and couldn't remember what I was running on them and didn't know if it would be the same or not anyway. Maybe I'll stick with the 14s to get the bigger G70s. Thanks folks!

[gto_ron]

I'm running 225-70 R15 on 15X7 rims with no problems. I'm using Diamondback redlines and am very satisfied with the tires and service. I know I'm kinda slow responding to this thread but we're all freezing in OH and I had to thaw out my laptop..