# Are these wheel and tire sizes okay?



## kevin1727 (Aug 4, 2021)

1964 Pontiac Tempest. Front has been converted to disc brakes, otherwise everything is stock.
I'm looking at this for wheels and tires:
Wheels all around - 15x7 wheels, 4.5" backspace.
Front Tires - 215/70R15
Rear Tires - 225/70R15
According to what I'm finding, the rear tires may be a little large on diameter, but my builder thinks they will be fine. We are trying to stay with largest possible diameter for highway engine rpm.
I compared all these to 205/75R14 which I think is comparable to stock tires, and according to wheel-size.com and discounttire.com they should work but I can't verify what the original backspace is for the stock wheels. I don't have the original wheels but think they might be 4" backspace from what I've read.
Anyway, I'm hoping someone here has used this combination and it worked.


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## Baaad65 (Aug 29, 2019)

I'm running 215/70/15, 4" BS on the front with UMI performance I" lowering springs on my '65 with no rubbing, I have 275/60/15, 4.5" BS out back with stock height UMI performance springs but I did have to make a little room in the well for the stock height springs as I was running 3/4" spacers before and if I hit a big dip the tires would scuff the inside of the outer rear well. Kinda wish I would have gone with 235/60/15 up front.


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## kevin1727 (Aug 4, 2021)

Baaad65 said:


> I'm running 215/70/15, 4" BS on the front with UMI performance I" lowering springs on my '65 with no rubbing, I have 275/60/15, 4.5" BS out back with stock height UMI performance springs but I did have to make a little room in the well for the stock height springs as I was running 3/4" spacers before and if I hit a big dip the tires would scuff the inside of the outer rear well. Kinda wish I would have gone with 235/60/15 up front.


Not sure about the '64 vs '65 but doing a tire comparison, those rear tires are bigger diameter and a lot wider than the 225/70R15. If those only hit on big dips, then the ones I am looking should be fine. 
Thanks!


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## Baaad65 (Aug 29, 2019)

I think '64 and '65 are pretty close but I'm not an expert, I started with 255/60 and had plenty of room. My 275's are 28" tall so it keeps the rpms in a decent range, I run about 2400 @ 60 mph with a 3:42 gear. I need all the traction I can get for my 461 so I run MT drag radials. If you need pix on how the tires look on mine let me know.


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## kevin1727 (Aug 4, 2021)

Baaad65 said:


> I think '64 and '65 are pretty close but I'm not an expert, I started with 255/60 and had plenty of room. My 275's are 28" tall so it keeps the rpms in a decent range, I run about 2400 @ 60 mph with a 3:42 gear. I need all the traction I can get for my 461 so I run MT drag radials. If you need pix on how the tires look on mine let me know.


I might look at 235/70's. From what you're saying that would give me the larger 28" diameter but not quite the width where your 275/60's were rubbing. That would allow me to still use 7" wheels all around. I'm still trying to find the stock wheel spec on the '64 to do a comparison on the wheel-size.com site.


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## kevin1727 (Aug 4, 2021)

I found the wheel spec but it shows "offset" instead of "backspace". It seems the two are related since the backspace changes whenever I change the offset on the wheel calculator. With the factory wheel as 14x6 with 8mm offset on the calculator, it shows a 4" backspace.


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## armyadarkness (Dec 7, 2020)

kevin1727 said:


> Not sure about the '64 vs '65 but doing a tire comparison, those rear tires are bigger diameter and a lot wider than the 225/70R15. If those only hit on big dips, then the ones I am looking should be fine.
> Thanks!


225/70 is much smaller than what you could run.


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## Baaad65 (Aug 29, 2019)

Yes they are related, look at tiresize.com they have a lot of tools. So you wouldn't want to go with 8" rims in back? Then you could do 245, 255, 265- 60's in front if you go with a 70 you have to watch not to go to big or it will rub on the corners because a 70 is a tall tire. Rallye I's are available in 8" x 15" if you're going for the stock look idk.


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## PDub (Sep 8, 2019)

I have 235/60/15's front and back on my 67 GTO. I'm definitley looking to upgrade from my Rally 1 to something else. I'm in no way a tire expert but was trying to do research on tiresize.com as suggested. For the tire size calculator and alternate tires, is it best to stay within the same tread width (235) to keep from having issues? I noticed there are other alternatives. I was thinking about going to a 17" wheel but unfortunately if I do then I lose the white lettering from my BF Goodrich tires. It seems they only do that on the 14 and 15" tires. Notthing screams old school muscle like the white leterring in my opinion. Also, does anyone stagger the front and back with back being larger width? I guess downfall to that would be if you wanted to rotate tires. Thanks for any recommendations.!!


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## kevin1727 (Aug 4, 2021)

I'm looking at 225/60R15 front like Baaad65 is doing and 235/70R15 rear which is bigger than what my builder suggested but a little narrower than the 275/60R15 that Baaad65 used and had some rubbing.
These would allow me to use 8" rims. For the tires my builder suggested I would need 7" rims. In the rim design I like the 7" ones are $120 more for the set than the 8" ones. 
I may have to send some PM's to the people with '64's on the forum to see what they are using.


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## Baaad65 (Aug 29, 2019)

kevin1727 said:


> I'm looking at 225/60R15 front like Baaad65 is doing and 235/70R15 rear which is bigger than what my builder suggested but a little narrower than the 275/60R15 that Baaad65 used and had some rubbing.
> These would allow me to use 8" rims. For the tires my builder suggested I would need 7" rims. In the rim design I like the 7" ones are $120 more for the set than the 8" ones.
> I may have to send some PM's to the people with '64's on the forum to see what they are using.


I'm running a 215/70/15 up front with an American Racing 7" wheel 4" BS, out back is 275/60/15 8"-















4.5" BS... I was thinking of changing the front to a 235/60 but since I lowered it I might have issues so I'm saving my money. The rake looks goofy because the garage floor slopes over an inch front to back, and I'll try and get a close up of the front later. These are stock height UMI performance rear springs with no spacers, the fronts are 1" lowering UMI performance springs.


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## Baaad65 (Aug 29, 2019)

Here's the fronts.


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## PDub (Sep 8, 2019)

Baaad65 said:


> I'm running a 215/70/15 up front with an American Racing 7" wheel 4" BS, out back is 275/60/15 8"-
> View attachment 149287
> View attachment 149288
> 
> 4.5" BS... I was thinking of changing the front to a 235/60 but since I lowered it I might have issues so I'm saving my money. The rake looks goofy because the garage floor slopes over an inch front to back, and I'll try and get a close up of the front later. These are stock height UMI performance rear springs with no spacers, the fronts are 1" lowering UMI performance springs.


Hey Bad65 - what is your measurement from the center wheel well to the floor for front and back? My 67 is 26" on the front but 23.5 " in the back. I'm thinking of raising the back up a bit to match the front or at least be an inch higher. The stance on your car looks good!!


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## Baaad65 (Aug 29, 2019)

PDub said:


> Hey Bad65 - what is your measurement from the center wheel well to the floor for front and back? My 67 is 26" on the front but 23.5 " in the back. I'm thinking of raising the back up a bit to match the front or at least be an inch higher. The stance on your car looks good!!


Thanks! The front measurement is 26 1/4" the rear is 25 3/4" with a full tank.


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## kevin1727 (Aug 4, 2021)

Baaad65 said:


> I'm running a 215/70/15 up front ....


Oops, sorry that was PDub running the 235/60.


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## armyadarkness (Dec 7, 2020)

I have 15x7 Rally 2 on my 67, and 245/70/15 fit without being anywhere near anything.


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## kevin1727 (Aug 4, 2021)

Baaad65 said:


> I'm running a 215/70/15 up front with an American Racing 7" wheel 4" BS....


I like the American Racing machined wheel with the black background because my car is black. On the Summit website it says those don't fit the 1964 Pontiac. However the Wheel Vintique steel Rallye II's do. I think it has something to do with the center bore.


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## kevin1727 (Aug 4, 2021)

PDub said:


> I have 235/60/15's front and back on my 67 GTO. I'm definitley looking to upgrade from my Rally 1 to something else. I'm in no way a tire expert but was trying to do research on tiresize.com as suggested. For the tire size calculator and alternate tires, is it best to stay within the same tread width (235) to keep from having issues? I noticed there are other alternatives. I was thinking about going to a 17" wheel but unfortunately if I do then I lose the white lettering from my BF Goodrich tires. It seems they only do that on the 14 and 15" tires. Notthing screams old school muscle like the white leterring in my opinion. Also, does anyone stagger the front and back with back being larger width? I guess downfall to that would be if you wanted to rotate tires. Thanks for any recommendations.!!


Look at the wheel-size.com site too. It shows clearance to suspension and wheel wells, and does comparisons between two wheels and tires.


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## Baaad65 (Aug 29, 2019)

kevin1727 said:


> I like the American Racing machined wheel with the black background because my car is black. On the Summit website it says those don't fit the 1964 Pontiac. However the Wheel Vintique steel Rallye II's do. I think it has something to do with the center bore.


Go to the American Racing site and put in your car, they should be the 120. something lug spacing and they have a wheel visualizer where you even can pick your car color, they will fit. I have a Chevy 12bolt and it's the same pattern as the front.


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## kevin1727 (Aug 4, 2021)

Baaad65 said:


> Go to the American Racing site and put in your car, they should be the 120. something lug spacing and they have a wheel visualizer where you even can pick your car color, they will fit. I have a Chevy 12bolt and it's the same pattern as the front.


American Racing shows them as okay. It's the VN501 500 series. The center bore is 72.6mm and Pontiac is 70.3mm, which seems miniscule to me.
(edited: I figured it out. The center bore is only critical for cars with bolts. For cars with cone lug nuts, the lug nuts center the wheels). 
How are they to take care of? Does the aluminum discolor or oxidize?


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## Baaad65 (Aug 29, 2019)

kevin1727 said:


> American Racing shows them as okay. It's the VN501 500 series. The center bore is 72.6mm and Pontiac is 70.3mm, which seems miniscule to me.
> (edited: I figured it out. The center bore is only critical for cars with bolts. For cars with cone lug nuts, the lug nuts center the wheels).
> How are they to take care of? Does the aluminum discolor or oxidize?


They haven't yet in six years but I only do about 700 miles a summer and clean them before every show. I had them red lined striped and bought some bubble decals for the center caps, I don't like being a rolling advertiser for companies if I can help it. Some other companies have similar wheels but more expensive, I bought mine on eBay from Rons rims.


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## kevin1727 (Aug 4, 2021)

Thank You to everyone who commented and helped me.
Here's what I'm going with as soon as I can place an order:
American Racing 15x7 VN50147034500
BF Goodrich 215/70R15 front
BF Goodrich 235/70R15 rear


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## armyadarkness (Dec 7, 2020)

Super cool. I've never seen those before. You might be the first guy here to get them.


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## 64Original (Jun 21, 2017)

kevin1727 said:


> 1964 Pontiac Tempest. Front has been converted to disc brakes, otherwise everything is stock.
> I'm looking at this for wheels and tires:
> Wheels all around - 15x7 wheels, 4.5" backspace.
> Front Tires - 215/70R15
> ...


Look at going to a 5" backspacing on the rear to get you a little extra room from the lip.


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## Baaad65 (Aug 29, 2019)

armyadarkness said:


> Super cool. I've never seen those before. You might be the first guy here to get them.


Really? I got them in 2017, where do you think he got the idea 😁 should I send you some of the 80,000 pix I have if you forgot 🤣


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## Baaad65 (Aug 29, 2019)

kevin1727 said:


> Thank You to everyone who commented and helped me.
> Here's what I'm going with as soon as I can place an order:
> American Racing 15x7 VN50147034500
> BF Goodrich 215/70R15 front
> ...


I'm sure you can fit 245 or 255 in the rear if you need more traction, I first had 255 with plenty of room. And alot of guys here I've seen are running 235/60 in front if you're not lowering it...just a thought 👍


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## Baaad65 (Aug 29, 2019)

kevin1727 said:


> Thank You to everyone who commented and helped me.
> Here's what I'm going with as soon as I can place an order:
> American Racing 15x7 VN50147034500
> BF Goodrich 215/70R15 front
> ...


Maybe you want mine then I could get 17's 😀 they are 15x7 and 15x8...tires too 👍


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## 67ventwindow (Mar 3, 2020)

Baaad65 said:


> Really? I got them in 2017, where do you think he got the idea 😁 should I send you some of the 80,000 pix I have if you forgot 🤣


 I dare you to.


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## kevin1727 (Aug 4, 2021)

I ordered but there is a one week delay on them getting the wheels in. I sure learned a lot about offset, back spacing, and tire sizing in my searching.


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## armyadarkness (Dec 7, 2020)

Baaad65 said:


> Really? I got them in 2017, where do you think he got the idea 😁 should I send you some of the 80,000 pix I have if you forgot 🤣


HOOK, LINE, AND SINKER!


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## Baaad65 (Aug 29, 2019)

67ventwindow said:


> I dare you to.


I would, but by the time they would download with my internet my grand kid that isn't born yet would be driving my car 🤣


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## armyadarkness (Dec 7, 2020)

67ventwindow said:


> I dare you to.


That joke took me weeks to plan and wait it out. It was worth it. Everyone in the bar was wondering why I was laughing all night.


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## kevin1727 (Aug 4, 2021)

64Original said:


> Look at going to a 5" backspacing on the rear to get you a little extra room from the lip.


I hope they are okay. Will probably be more chance of interference on the diameter than the width. I'll have to limit bouncing in the back seat to when the car is not moving.


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## Baaad65 (Aug 29, 2019)

kevin1727 said:


> I hope they are okay. Will probably be more chance of interference on the diameter than the width. I'll have to limit bouncing in the back seat to when the car is not moving.


I'll let you know how my new rear springs do on the up and downs in April...unless I turn the heat up in the garage and talk the wife into " helping " me with something in the back seat...she said she's up for it, that's makes two of us 😉


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## kevin1727 (Aug 4, 2021)

Baaad65 said:


> ..... I had them red lined striped and bought some bubble decals for the center caps, I don't like being a rolling advertiser for companies if I can help it. .....


Where did you get the bubble decals? I will want to cover mine too.


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## Baaad65 (Aug 29, 2019)

kevin1727 said:


> Where did you get the bubble decals? I will want to cover mine too.


They are from 3dcarstickers.com they are in the Ukraine and I specced the 40mm but 41mm would probably fit a little better in the American Racing center caps. They came in black or red, and were cheap so I ordered a set of each then peeled apart the black ones cutting out the Pontiac arrowhead for my breathers and air cleaner nut.


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## kevin1727 (Aug 4, 2021)

Baaad65 said:


> They are from 3dcarstickers.com they are in the Ukraine and I specced the 40mm but 41mm would probably fit a little better in the American Racing center caps. They came in black or red, and were cheap so I ordered a set of each then peeled apart the black ones cutting out the Pontiac arrowhead for my breathers and air cleaner nut.


Thanks! Those will be perfect !


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