#1  
Old 01-31-2025, 04:13 PM
tmataraza tmataraza is offline
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Default Rims and Tire sizes for a 66 Cat

Hey all, I've been searching this forum and have read a lot of them regarding this topic (esp the sticky) but Im not much of a mechanic when it comes to "what works". Im more of a learn to replace/fix what's there kind of tinkerer.

I want to upgrade my wheels and tires on my 66 Catalina that is all original. The 215/75/B14 tires that are on the car are original also. They are the bias ply type.

I intend to keep the tires and rims I take off the car, but I want to put 15 inch cragars on them. I found these https://www.summitracing.com/parts/crr-325899#overview (and I live close to the OH store).

What I would like to use is the 215/70/R15 tires with this rim, but I cant make out if the front end would have any rubbing. Most of what I'm reading is backend will fit these as they are physically the same width and height tire as my current, but they might rub in front? Is my only solution a "just buy it and hope"?

Thanks for the help!!
Pics of the car for sake of pics of the car!
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  #2  
Old 01-31-2025, 05:15 PM
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No way any 15x8” wheel with such a shallow backspace dimension of 3.88” will work.

Getting a 15x8” wheel to fit is difficult enough already, these cars as big as they are have limited space inside the wheel wells. A 15x7” wheel with be tight even with the proper backspace dimension of around 4.5”, the rear wheel wells are particularly tight on these cars.

Find a stock wheel without a tire on it. Bolt it on and put about a 4” wood block under it and set the car’s weight down on it. Measure using a straight edge to the outer and inner points of the wheel well.

This is how you get an idea of what will work, using a stock wheel as a reference. One thing is for sure, those wheels will push the tire outward too far.

The makers of most of these 15” aftermarket wheels are so dumb for offering wider wheels with such shallow backspacing. Unfortunately you are encountering the same exact issue as hundreds of others trying to buy wheels for 60s and 70s American classic and muscle cars.

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  #3  
Old 01-31-2025, 08:19 PM
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Default wheels

i have a set of 15x8 weld pro stars with a 5" backspace that fit as well as a 15x7 with 4.5 backspace

im also working on a set of 18x8 with a 5.75 backspace that will fit with skirts and a 235/50/18


the weld wheels are for sale

  #4  
Old 02-01-2025, 11:34 AM
tmataraza tmataraza is offline
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Thank you both for the responses.

Can you send a picture of the weld wheels for sale and the price?

Also, thank you Mr B for your insight. This is why I posted and not just bought. The backspacing measurement is what is confusing me. Unfortunately I don't have the car local enough to go measure it. I'll just have to wait for spring I guess. Currently 4" of snow on the ground and 40 mins from where I store it.

  #5  
Old 02-02-2025, 02:45 PM
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Default wheels

pictures
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  #6  
Old 02-02-2025, 03:24 PM
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Backspacing and other terminology are explained in this diagram:
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Old 02-02-2025, 04:13 PM
tmataraza tmataraza is offline
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Quote:
Originally Posted by imposter View Post
pictures
Thank you, but I think I'll pass.

  #8  
Old 02-02-2025, 04:15 PM
tmataraza tmataraza is offline
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Quote:
Originally Posted by b-man View Post
Backspacing and other terminology are explained in this diagram:
Dude. This is helpful. Thanks so much. This spring I'll pull a rim off the car and measure what I got and go from there now that I know what I'm measuring.

Just went to go look at a new house last night out of the blue and made an offer. If this happens, rims will have to be next year's project.

Thanks both of you for the information!

  #9  
Old 02-04-2025, 06:18 PM
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here are some measurements with and without the skirt

  #10  
Old 02-04-2025, 06:24 PM
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attach
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