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Backspace on 17 X 8 wheels

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Old 01-17-2017, 09:37 PM
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OldCarBum
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Default Backspace on 17 X 8 wheels

I'm changing from 15" X 8" wheels with a 4" backspace to 17" X 8" wheels for the upgrades I'm making on my '73. The wheel manufacturer is thinking that I should go to 4.25" or 4.5" backspacing to accommodate for the more squared off side wall to tread design on 17" tires. I've looked through numerous threads which shows about 50% of you are running 4.5" and about 50% of you are running 4" backspace. I would like to run the wheels without having to add spacers if possible. Can you give the reasons you chose 4.5" over 4" backspacing.
Old 01-17-2017, 10:26 PM
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Metalhead140
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4" backspace will be better every time. A lot of people run 4.5" backspace on 17x8s because wheels are more readily available in that backspace, not because it's in any way better...
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Old 01-18-2017, 01:05 AM
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Originally Posted by Metalhead140
4" backspace will be better every time. A lot of people run 4.5" backspace on 17x8s because wheels are more readily available in that backspace, not because it's in any way better...
That's the same thing the wheel manufacture is stating. He has the 4.5" backspacing in stock but he states the 4" is better balanced, centering the mounting plate in the center of the wheel and the wheel/tire weight is closer to being centered over the wheel bearings.
I'm thinking of staying with the 4" backspace.
Wilwood brake systems agrees with the wheel manufacturer.

Last edited by OldCarBum; 01-18-2017 at 10:43 AM.
Old 01-18-2017, 02:20 AM
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ddawson
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Not a great pic but these are 18x8 4" backspace.

Pretty square side wall and it's perfect.



Old 01-18-2017, 07:23 AM
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Metalhead140
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Originally Posted by ddawson
Not a great pic but these are 18x8 4" backspace.

Pretty square side wall and it's perfect.



That looks good! Most pics I've seen with 4.5" backspace wheels look like the wheels sort too far inside the guards to me, but yours looks nice. What size tyres?
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Old 01-18-2017, 10:26 AM
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69Vett
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beautiful car, like the stance on your car.
these are 17" wheels. on 69 sitting high in the back due to no interior.
overall back spacing; 4" in front, 4.25 in the rear.
4.5 stuck the wheels out to far, i tried them.


Last edited by 69Vett; 01-18-2017 at 11:02 AM.
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Old 01-18-2017, 12:16 PM
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ddawson
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I'm using a 255/45/18
Old 01-18-2017, 04:37 PM
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resdoggie
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My 18"X9.5" with 5-1/4" BS and a 275/45-18 tire. The tire is abouut flush with the top of the fender. I needed to relocate parking brake bracket. No spacers on stock trailing arm.


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Old 01-18-2017, 04:57 PM
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ElCid79
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I have 18 with 4.5 because I didn't want to pay the super high dollar needed to have them custom made. They honestly look fantastic. I will post a photo later.
Old 01-18-2017, 05:50 PM
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The price on these wheels is the same. I just have to wait for the 17X8's because they are not in stock.

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