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Discussion Starter · #1 ·
HI Folks,

If you could recommend biggest 15" Rear Tire & Wheel combination for my 1965 GTO?

Look for the widest, fat rear end look without modifying the rear fender lips.

Thank you in advance.
 

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I have 275/60/15 MT drag radials on 15x8 rim's on my '65 with 3/4" spacers under the stock springs and it's tight but no rubbing on bumps, like the stance without the spacers but the tires rub on larger bumps so when I get it painted I'm going to have them make some more room in the well. Would someday like to run 17" so it looks more modern.
143216
143217
 

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Thanks, some GM color I got it that way and love it, guess it was red originally, I think 4.5 or 5 what ever it shows on the American Racing site.
 

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Idk because there's only maybe an inch on the inside from tire to frame, and idk if there was a choice on the MT website but these were the most popular setback and got them through Ebay...I didn't know how to check setback and my tire person wasn't much help, he said to buy 255 that 275 would never fit so that's what bought first then when we mounted them he says I could've went bigger, I wanted to strangle him because then I couldn't return the tires after they been mounted so had to sell them for half and bought 275. Then when you installed the 461 the Sportsmen's had no traction so changed them out again to the drag radials and giving away some more tires, I'd really like 17" but the tires are slightly larger and they reccomend a 9" rim over my 8"s so they would never fit until I make some room in the wheel well but maybe with a 5" setback it's a possibility I just need a good way to measure things and a bunch more money...I'll work on making these tires bald 🤣
 

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Anybody out there have 17" wheels on their goat and what size tires especially for a '65? Like to do the front too but got to watch the clearance as I'm running 215/70/15 now with 1" in lower springs and the just clear everywhere even on big dips and bumps. Guy that did my alignment said wider tires up front would wander...you know I just kinda didn't put a lot of thought to sizes as I just got back into the game after 30 years on the sidelines and thought 15" was a big upgrade from 14" but after a couple years going to shows my 15" tires look like balloons but I'm not crazy about the 20" and up look on 60's cars. I want to stick with the same wheels and they only come in 15" and 17".
 

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I don't remember the size of rear tire that was on the car when I bought it (mid 2000's).... but these are balloons (not photoshop!)
143315


I quickly changed to 215/60R15's. I like the look of stock size tires.

143316
 

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Beautiful GTO!

I was going to go with 15 X 8 rear rims.
15 x 8's were a fairly standard rim used back in my time. The key is the tire size. You will have thread width BUT the thing you want to know is sidewall width. Example, you can have a 9" wide tread width and 11" wide side wall section.

Most tires will have a recommended rim width range. The width of the rim seems to be what affects the section width, not the tread width as that always stays the same. This is why you see some of the contemporary cars/trucks with funky looking sidewall bulges as they purposely get rims/tires to make this look. From my researching, you don't want a rim too narrow for a wide tire as the narrow rim will draw the sidewalls/tire bead way in (like squeezing it together) and the angle that the side wall will take as it rides on the rim can become too excessive and the rim can over time cut into the sidewall at the bead rather then the bead/sidewall ride in a more vertical position where the rim won't be grinding/cutting into it as the tire flexes about - or possibly slip on those really good traction days.

The Metric tires are rated a bit different than in my time, so just try to get your tread width, section (sidewall) width, tire height, and recommended rim sizes. Keep in mind that tire size changes (height) can affect your speedo accuracy.

If your suspension is worn, side-to-side play that will affect axle centering should be thought about. The rear-end will move/shift about as the car goes down the road, so allow room for this. In my experience, most of the rubbing, if any, seems to be in the wheel well due to its shape. Weak coil springs will have the car moving up and down and you want to take into acount any hard bumps that may cause the suspension to bottom out and put the tire higher into the wheel well when it does.

You may also want to google Chevelle of the same year as they would be a similar fit.
 

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Discussion Starter · #19 ·
15 x 8's were a fairly standard rim used back in my time. The key is the tire size. You will have thread width BUT the thing you want to know is sidewall width. Example, you can have a 9" wide tread width and 11" wide side wall section.

Most tires will have a recommended rim width range. The width of the rim seems to be what affects the section width, not the tread width as that always stays the same. This is why you see some of the contemporary cars/trucks with funky looking sidewall bulges as they purposely get rims/tires to make this look. From my researching, you don't want a rim too narrow for a wide tire as the narrow rim will draw the sidewalls/tire bead way in (like squeezing it together) and the angle that the side wall will take as it rides on the rim can become too excessive and the rim can over time cut into the sidewall at the bead rather then the bead/sidewall ride in a more vertical position where the rim won't be grinding/cutting into it as the tire flexes about - or possibly slip on those really good traction days.

The Metric tires are rated a bit different than in my time, so just try to get your tread width, section (sidewall) width, tire height, and recommended rim sizes. Keep in mind that tire size changes (height) can affect your speedo accuracy.

If your suspension is worn, side-to-side play that will affect axle centering should be thought about. The rear-end will move/shift about as the car goes down the road, so allow room for this. In my experience, most of the rubbing, if any, seems to be in the wheel well due to its shape. Weak coil springs will have the car moving up and down and you want to take into acount any hard bumps that may cause the suspension to bottom out and put the tire higher into the wheel well when it does.

You may also want to google Chevelle of the same year as they would be a similar fit.
Jim,
Thank you
 

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Good information, I'm running 8" rims in back 7" up front, if I want 17" rims the only 28" tall ET SS drag radial recommend a 9" rim and the tire would be a 305/45/17 pretty big and I would definitely need some wheel well massaging but I want to stay with 28" tall so my rpms don't get any higher at highway speeds.
 
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