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ZOE
08-29-2015, 09:45 AM
any suggestion on what is widest 14 or 15" tire that will fit on rear stock supension 57 belair,
using 8" rims, or if can use a 10" rims
just don't want to try and buy,

Rick_L
08-30-2015, 05:06 PM
A 275 tire on a wheel with the correct backspacing will barely fit, there is no room for error.

Chevynut did a spreadsheet years ago on wheel and tire fit and clearance. It is still on the internet somewhere.

ZOE
08-30-2015, 05:26 PM
Thanks, i'll try and look it up, so 295-50-15 are out.

JT56
08-30-2015, 07:43 PM
Thanks, i'll try and look it up, so 295-50-15 are out.

Yes a 295 will not fit with a leafs in the stock location. If you try to fit a 275 drag radial on a 8" rim it will require you bend the lip on the quarter panel.

chevynut
08-31-2015, 08:02 AM
Yes a 295 will not fit with a leafs in the stock location. If you try to fit a 275 drag radial on a 8" rim it will require you bend the lip on the quarter panel.

JT, what makes a 275 drag radial different than any other 275 tire? Are you sure the issue isn't just getting the right offset?

Rick_L
08-31-2015, 08:45 AM
I don't see how the tire being a drag radial makes a bit of difference, at least the ones I've seen.

A 275 tire will fit on a stock 57 with no problem. I think that also applies to 55-56.

This assumes that the body is on the frame symmetrically, and the body is stock and undamaged.

But it is a very tight fit. Far better to have the springs moved or even a mini-tub, as well as a slightly narrower than stock axle. Just makes things easier and more forgiving.

JT56
08-31-2015, 08:49 AM
JT, what makes a 275 drag radial different than any other 275 tire? Are you sure the issue isn't just getting the right offset?

When I changed to a drag radial, I had to trim the lip on the inner fenders to keep them from rubbing. No other changes, same wheel(rim), offset and rear suspension! I assume the bulge of the sidewall. Both were 275/60/15?

chevynut
08-31-2015, 09:04 AM
When I changed to a drag radial, I had to trim the lip on the inner fenders to keep them from rubbing. No other changes, same wheel(rim), offset and rear suspension! I assume the bulge of the sidewall. Both were 275/60/15?

The sidewall bulge is where the 275mm is measured. I'm guessing your offset isn't optimal for a 275 tire and perhaps the street tire you had wasn't truly a 275 width. Tires do vary somewhat. On a stock rearend zero offset or a very slightly positive offset works best.

The fenderwell lips on these cars are typically 71.5-72" wide and the springs are 48" wide outside. That makes the center of the wheel tubs about 59.75-60" across and the tubs about 11.75-12" wide each if the body is centered, accounting for the springs. A true 275 tire would be 10.8" wide at the bulge leaving 1"-1.25" of space to work with. You could go as close as 1/4" to the spring, imo, with no issues. That would put the center of the tires at 59.3" requiring an offset of a little over +1/4" and would give you at least 3/4" to the fenderwell.

chevynut
08-31-2015, 09:11 AM
When I changed to a drag radial, I had to trim the lip on the inner fenders to keep them from rubbing.

You don't have a stock rear axle, do you? Do you know the axle width and the wheel offset?

JT56
08-31-2015, 09:40 AM
I was running a Firestone Indy 500 tire with 32 to 35 psi of air in them. I am currently running a Mickey Thompson on the car(with pressures running from 12 psi up...depending on track conditions). That maybe where the bulge differs? I haven't looked into the sidewall thickness either. I know on my car what I had and what I had to do. Something worth noting with this topic...most people try to stuff the largest tire under these cars without making any modifications. However some don't really consider the application/setting. Yeah it might fit in there, but driving around with uneven roads...they may rub. For that reason, that is why I removed the leafs and went a different direction. Still need to mini tub

JT56
08-31-2015, 09:45 AM
You don't have a stock rear axle, do you? Do you know the axle width and the wheel offset?

When I first put the drag radials on. I had a stock 56 rear end(60" face to face) with leafs in the stock location. I cant remember if they are 4 1/4 or 4 1/2? Been awhile. Now my 9" is 58.5" from rotor face to face. I am having to use 1/2 wheel spacers to center them. Once the mini tub is done then I will order new wheels.

567chevys
08-31-2015, 10:13 PM
A 275 tire on a wheel with the correct backspacing will barely fit, there is no room for error.

Chevynut did a spreadsheet years ago on wheel and tire fit and clearance. It is still on the internet somewhere.

Its on this site up at the top on the Tool Bar under Calculators

567chevys
08-31-2015, 10:14 PM
A 275 tire on a wheel with the correct backspacing will barely fit, there is no room for error.

Chevynut did a spreadsheet years ago on wheel and tire fit and clearance. It is still on the internet somewhere.

Its on this site up at the top on the Tool Bar under Calculators

Sid

Rick_L
09-01-2015, 04:34 AM
I didn't know it was so close at hand. Good job, Sid.