[orange'66]

I'm planning on putting 255/60r15's on 15x7 wheels for the rear of my '66 nova. Now I know everyone says to run 4.5" backspacing on this setup, but I found some rims that I like that have 4.25" backspacing. Do you think I'll have rubbing problems? Thanks!

 

[wskaiser]

Only one really sure method of knowing is to mount them. There is quite a variation from car to car with the early models and what fits one will not fit another. You can do a lot of measuring but mounting them is the best way to tell. There can also be a size difference from one tire brand to another tire brand of the same size.

 

[NovatoriusRex]

With that little backspacing (4.25"), you're going to have trouble fitting a 255 tire in there. On a good day, a 235 is a tight, but good fit. On an even better day, a 245 will fit.

You'll need to measure you car to see what backspacing will work best and how much clearance you have (axle to body, axle to springs) around the wheel mounting surfaces on your rear axle.

 

[mychevyii20]

I have 15x7x4.5 with 235 60 15 tires. They center perfectly with just under 2 fingers of clearence left. 255 very doubtful on stock fenders with 4 1/4 backspace,

When measuring, measure the spring to rim distance in front of the wheel. The stock springs have a slight angle and clearences are closer/tighter in front of the rear end. .

 

[OB_67_Nova]

I have 245 - 15 retreads with 15 X 8 X 4.5 ralley rims on my 67.
The drivers side is cool, but had to take the grinder to the passenger side lip.
They rub when the body flexes side to side only.
When I put the final tire/wheel combo on I will be going with 235s.

 

[Seattle_Mike]

"Everyone" DOES NOT say 4.5" backspace is correct. As the other posts read, measure YOUR car to see what space you have. I can't stress how important this is.
I see all these comments about "grinding", "bending", "cutting", "tweaking", "rubbing", when a little time spent measuring, researching tire section width for a specific brand & size tire, and sourcing a wheel/tire combo with the correct backspace to center it in the wheel opening, can save you so much grief and wasted money on a wrong combination that can look strange and worst of all possibly be unsafe.

 

[teddisnoke]

There are some measuring tools out on the market currently, but I fabbed up a very simple "tool" using an old piece of aluminum angle and another piece of 1/4-20 threaded rod from the local hardware store. Using this with the common accepted idea that the sidewall "bulge" off the outermost portion of your rim should be no greater than 1" on each side (some will go down to 3/4")for your tire, you should be able to measure and choose with confidence what size rim works best for your specific car. Dale