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Tire question (Asking input)

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Old 02-06-2017, 04:38 PM
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golfboy
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Default Tire question (Asking input)

I have a 78 Pace Car and have the standard size 255 60R15 tires and aluminum wheels on it. There is enough room between the top of the tire and the edge of the wheel well lip to slide all four of my fingers in. This is on both the front and rear wheel wells. I don't like the look of all of that space and would like to fill it with taller tires. I am not interested in lowering the car with the front air dam that I have. So, I am thinking about replacing all four tires with 235 75R15 tires which are taller and would fill the extra space nicely. My question is, is this a viable option or would it look stupid? Does anyone out there run these size tires on their C-3? Any input would be appreciated.
Old 02-06-2017, 05:03 PM
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Alan 71
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Hi gb,
The 235/75 tire is almost 2 inches taller than the original tire on you car.
I'd be concerned that the amount of sidewall showing will look as though you've put truck tires on your car. Remember half of that dimension will fill the wheel well but the other half will raise the car up off the ground.
I think I'd want to know why there are 4 fingers of distance between your present tires and the top of the wheel arch. Something is causing that.
Regards,
Alan

Last edited by Alan 71; 02-06-2017 at 05:06 PM.
Old 02-06-2017, 05:53 PM
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leadfoot4
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A couple of points to consider.....

235/75/15 tires are indeed, borderline "truck" tires, these days, and along with not being available AT ALL with any kind of performance rating, they're NOT approved for an 8" wide rim, assuming you're referring to a stock sized, 15x8" rim.

Maybe a couple pictures of your car would be helpful, so we're seeing what the issue is. One other thing, if you're not the original owner of the car, maybe somewhere along the line, somebody "screwed" with the car in the past, and it's now at something above the design ride height. again, pictures would be helpful.
Old 02-06-2017, 06:00 PM
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doorgunner
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Originally Posted by Alan 71
Hi gb,
The 235/75 tire is almost 2 inches taller than the original tire on you car.
I'd be concerned that the amount of sidewall showing will look as though you've put truck tires on your car. Remember half of that dimension will fill the wheel well but the other half will raise the car up off the ground.
I think I'd want to know why there are 4 fingers of distance between your present tires and the top of the wheel arch. Something is causing that.
Regards,
Alan
Alan has good points: 75 series will actually make the tires appear narrower. 70 series will fill the wheel wells and look wide. Lowering the rear of the car an inch or so AFTER installing new tires will have a minimum effect on the air dam IMO.
Old 02-07-2017, 08:50 AM
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Old 02-07-2017, 08:58 AM
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I appreciate the responses that I have gotten and have posted a picture of my car to show what I am talking about. The bushings in the front and rear of the car have been replaced. I am reconsidering my tire choice as posted and now think that 235 70R15 or 225 70R15 tires might be best. What do you think?
Old 02-07-2017, 09:06 AM
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Bills17n72
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Originally Posted by golfboy
I appreciate the responses that I have gotten and have posted a picture of my car to show what I am talking about. The bushings in the front and rear of the car have been replaced. I am reconsidering my tire choice as posted and now think that 235 70R15 or 225 70R15 tires might be best. What do you think?
if it was me ,I would have one front and one rear put on one side of the car to see what it looks like ,and dont move the car ,if you dont like them tell the tire place you dont want them ,I would think if you dont drive the car ,then there shouldnt be a issue of not wanting them ,I had the 225s on my 79 and they looked nice!!!oh by the way do you need a new emblem for the rear gas tank lid ,I have one if need be!!!

Last edited by Bills17n72; 02-07-2017 at 09:08 AM.
Old 02-07-2017, 09:15 AM
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Originally Posted by golfboy
I appreciate the responses that I have gotten and have posted a picture of my car to show what I am talking about. The bushings in the front and rear of the car have been replaced. I am reconsidering my tire choice as posted and now think that 235 70R15 or 225 70R15 tires might be best. What do you think?
I'm not trying to be overly critical, just helpful. Personally, I think your car looks a little "high" to me. When control arm bushings are replaced, and are tightened up without the full weight of the car on the suspension, this can happen.

Having said that, I would recommend the 225/70/15 tires. That was an OE size in '78.
Old 02-07-2017, 09:29 AM
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Alan 71
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Hi gb,
The "section width" on both the tires you list will be considerably narrower than the 255/60 tires.
The taller tires will be closer to the arch but will not fill the wheel well in the same way.
Here's an example of the affect of "section width".
Both tires are about the same height.
Regards,
Alan


255/60


215/70
Old 02-07-2017, 10:52 AM
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I wish my gap was as small as yours. I'm told that mine will drop down some when I install the interior components and all of the door hardware but I'm skeptical. Nice looking Pace Car.
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Old 02-07-2017, 11:03 AM
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Originally Posted by golfboy
The car looks "level" in the pic. Is that the reason you didn't want to "affect the air dam" by lowering the rear?

If so......going with "taller" tires is the only option since you do not want to "lower" the front suspension.

235/70 series would really fill in the wheel wells more than 225 series...and you could still rotate them without clearance problems while making sharp turns into driveways/etc.

Last edited by doorgunner; 02-07-2017 at 11:04 AM.
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Old 02-07-2017, 11:29 AM
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Originally Posted by doorgunner
The car looks "level" in the pic. Is that the reason you didn't want to "affect the air dam" by lowering the rear?

If so......going with "taller" tires is the only option since you do not want to "lower" the front suspension.

235/70 series would really fill in the wheel wells more than 225 series...and you could still rotate them without clearance problems while making sharp turns into driveways/etc.
Doorgunner, that is exactly what I am thinking! I could always lower the back of the car with the spring bolts but I don't want the rear of the car lower than the front and I don't want to lower the front with the air dam that I have. So, after checking a tire size chart I found that the 235 70R15 tire would only be .7 of an inch narrower that the 255 60R15 tires that I now have and would be taller by an inch to give me what I'm looking for. Besides, the 60 series tires that I now have look a little too fat for my taste.
Old 02-07-2017, 11:31 AM
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Originally Posted by golfboy
Can you provide pictures of the rear suspension including the outer spring bolts and the angle of the half shafts relative to the ground?
Old 02-07-2017, 11:34 AM
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Originally Posted by golfboy
I appreciate the responses that I have gotten and have posted a picture of my car to show what I am talking about. The bushings in the front and rear of the car have been replaced. I am reconsidering my tire choice as posted and now think that 235 70R15 or 225 70R15 tires might be best. What do you think?
A 225/70-15 is virtually the same diameter tire as a 255/60-15 which is what you have (27.4 vs. 27.1 for the 255). A 235/70-15 is ~ 28" so it will add a 1/2" more ground clearance and fill the gap between body and tire by a 1/2" over your 255/60's.

The sidewall of the 225/70 is 157.5mm while the 255/60 has a sidewall of 153mm. The only thing the 225/70 will do for you is give you a tire 30mm (1 - 3/16") narrower.

After changing the suspension bushings, these cars will tend to sit a bit high for a while until the bushings settle. If your car doesn't settle down to what it left the factory at in a few hundred miles you can easily drop the car an inch and all of it fill the wheel well. Just remove a coil from each spring up front or switch to the F-41 (FE7) springs. Then lower the rear by simply changing the rear spring bolts to 8" ones and adjust them to lower the rear an inch.

This is the typical ride height of a '78 Pace Car for comparison. All of them came with the 255/60-15.





Good luck... GUSTO
Old 02-07-2017, 11:46 AM
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Originally Posted by MelWff
Can you provide pictures of the rear suspension including the outer spring bolts and the angle of the half shafts relative to the ground?
MelWff, I can't get a picture at the present time, my digital camera needs recharging and I don't have a smart phone, just a Flintstone flip phone. LOL.
Old 02-07-2017, 09:58 PM
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Since it's a Pace Car, and it came from the factory with the racy looking 255/60/15's, if it were me, I would stay with 255/60/15's, and give the car some time to settle.
Your car had some special trimming done on the inner wheel well lips at the factory to accommodate the 255's, with the wider, lower profile (for the time) tires being a part of the overall Pace Car design; always have thought it was very nicely executed.
Looking at the photo you posted, IMO, the rear height, while a tad high, looks fine. The front does look like it's up higher than optimal, so if it doesn't settle after several months, then I'd also think about removing a coil, as mentioned by gusto14 above, although that stiffens the spring rate.
Re: lowering the front, I don't think you have to worry about the front air dam scraping, 'long as you're careful...The car will look better and you'll also lower the car's center of gravity a bit for better handling. Just my 2 cents...
Last spring, my '71 was sitting quite high after new springs front and rear, new shocks, and all new suspension bushings, and it initially bothered me, but there has been some settling and it definitely looked better after 1000 miles of driving it last summer. Hoping it'll drop a bit more...
Looks-wise, it could be argued that stance is everything!

Last edited by Bally; 02-07-2017 at 10:24 PM.
Old 02-07-2017, 10:23 PM
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I bought my 81 in 1991 before the whole lowering fad was in. it had the 255/60 in the front and 265/60 in the rear which filled up the well real nice. I recall them being Eagle NCTs. Of all the size tires they have now, they don't make that size and i still haven't gotten over it.

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Old 02-07-2017, 10:50 PM
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Here are a few pics of my 79 with stock suspension and 235/70R/15s on all 4 corners... I am still planning on lowering the car.



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Old 02-08-2017, 08:25 AM
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Originally Posted by golfboy
The bushings in the front and rear of the car have been replaced.
Was the front of the car on the ground when you tightened the control arm bushing bolts?
Old 02-08-2017, 08:44 AM
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Originally Posted by 79C3tnd
Here are a few pics of my 79 with stock suspension and 235/70R/15s on all 4 corners... I am still planning on lowering the car.



Thanks for the pictures of those 235 70R15 tires. I'm not interested in lowering my car any more from what is, just want to fill some of the space between the top of the tire and the wheel lip on the fender. I think those tires will do the job and they don't look as fat as the 255 60R15 tires that I presently have.


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