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Old Aug 21, 2013 | 06:39 PM
  #1  
Macadoo's Avatar
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From: Central Illinois
Need wheel size verification

Hey guys,
I'm ready to buy my wheels and just want to run the specs by everyone.
'71 Cutlass completely stock...drums all around.

Rear: 15x8 Cragar SS with 275/60/15 with 4.5" backspacing
Front: 15x7 Cragar SS with 235(or 245)/60/15 with 4.5" backspacing

I don't want a HUGE difference between the front and rears, just some. But I also don't want to make the front tires so large that steering starts to wander (I did read Ziff's post about alignment).
I like that "sucked-in" look when the tire is a lot wider than the rim. Will I get that with the 275 on an 8" wide rim? And does the tire wear faster because of it?

I'm assuming the one-piece Cragars are better than the two-piece.

Also, I'm going to jack it up a bit in the back, probably with Hotchkis airbags or possible air shocks. But if i understand correctly I need to make sure the wheel tire combo still tucks into the well without rubbing, true?

Thanks everyone,
-Mac
Old Aug 21, 2013 | 08:26 PM
  #2  
oldcutlass's Avatar
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Your choices are fine and what ever you decide looks better on the front will work.
Old Aug 22, 2013 | 04:35 AM
  #3  
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And just to be sure, I need 4.5" backspacing on the fronts? That sounds like a lot to me.
Old Aug 22, 2013 | 08:43 AM
  #4  
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Originally Posted by Macadoo
And just to be sure, I need 4.5" backspacing on the fronts? That sounds like a lot to me.
I would have expected more like 3.75" backspacing on a 7" wide wheel.
Old Aug 22, 2013 | 11:54 AM
  #5  
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I have Cragar 15x8 with 275/60R15's in back and 255/60R15 on 15x7 in front. Not sure about the backspacing and can get a slight rub in front if conditions are just right (dip & turn). It's a '69 but may help.
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Old Aug 22, 2013 | 02:39 PM
  #6  
s i 442's Avatar
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They don't make a 15X8 Cragar with 4.5 backspacing or I would already have them on my car!
And you would be better off with a 225/70 on a 7 inch rim for the front, plus no more than 4 backspacing up front.
Old Aug 22, 2013 | 04:58 PM
  #7  
Macadoo's Avatar
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From the Cragar website:

Part Number:
610C583445
Size:
15x8
Part Description:
15x8 S/S 1-pc Chrome
Bolt Pattern:
5x4.75
Offset:
0
Backspacing (In)
4 1/2"
Load Rating:
1900
Weight:
19
Cap Part Number:
361031CR

However, I'm still confused about the front wheel backspacing. But I think I have a handle on how to make the calculations after taking measurements.

s i 442, why do you think the smaller tires up front would be better? Better looking, better fit, or better steering?
And just out of curiosity, did you change up your springs and rockers with that mild cam?
Old Aug 22, 2013 | 06:11 PM
  #8  
s i 442's Avatar
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[QUOTE

s i 442, why do you think the smaller tires up front would be better?What you picked is short and fat.
And just out of curiosity, did you change up your springs and rockers with that mild cam? Im running the Comp Cams 490/280 magnum cam.[/QUOTE]
You can use up to a 500 lift cam with stock rockers torqued at 20lbs. You should change your valve springs but I never do if the engine is in the car.
I ran a 496 Crane cam in a 350 Olds and it was great. 3500 stall and 342 gears.
Oh and when I hear "Cragar" I still think of the old series and they are only 4.25 backspacing.


I like the looks of the one you picked out and with 4.5BC!!!


Last edited by s i 442; Aug 22, 2013 at 06:30 PM.
Old Aug 22, 2013 | 06:47 PM
  #9  
Macadoo's Avatar
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I thought about 70s but was afraid they would rub but I would probably have that problem with a wheel that's too wide. But as far as backspacing for the front 7 inchers, this is what Cragar lists for the 15x7 for '68-81 Cutlass:

Part Number:
610P573442
Size:
15x7
Part Description:
15x7 S/S 1-pc Polished
Bolt Pattern:
5x4.75
Offset:
+6
Backspacing (In)
4 1/4"
Load Rating:
1900
Weight:
18
Cap Part Number:
361031CR
Old Aug 22, 2013 | 10:09 PM
  #10  
s i 442's Avatar
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Right now my car has 235/70/15s, all the way around, you talk about a big ole tire.
I have ordered some rear springs for the back to drop it down so I can buy some new 225/70/15 all the way around on my 7 inch rims.
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