tire size

[ZOE]

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]

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]

Thanks, i'll try and look it up, so 295-50-15 are out.

[JT56]

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]

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]

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]

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]

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]

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]

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