Front wheel and tire size question

[c9zx]

1966 Cyclone, same as Fairlane  I think, 15x7 magnums, 4.25 inch back spacing, stock suspension, 1967 Mustang disc brakes. Does someone know if a 235x60x15 tire clear everything? Thanks, Chuck

[Rory428]

I don`t recall what the factory backspacing on original Magnum 500 wheels were, but years ago, I owned a 69 Cobra fastback, with Magnum 500s, and 235/60R15 tires, and the inner sidewalls slightly rubbed on the upper control arms, which 1/8" spacers corrected.

[Jb427]

15inch with 4.5 inch back space will hit the side of the upper control arm before full steering lock that is the place to look at. I run a 15x8 4.5back space with a 10mm spacer and a 225 50 15 tire but my car is lowered around 4 inches in the front. I think the tire will be fine but the 4.25 inch backspace may still hit the upper control arm it will get closer the higher your car is too.
I thought when I had magnum 500 wheels on my car I had 15x8 with a 4inch back space but I cant seem to find that size now and 15x10 with a 5inch back space on the rear

[6667fan]

Seems like a lot of back spacing for a front wheel. More appropriate for the rear. You already have the rims?

[c9zx]

Yes, I have the rims. All of the steel 15x7 Magnums I found had 4.25 back spacing. A previous set had the same back spacing.

[c9zx]

JB427, what size tire do you have on the rear 15x10 rim? If it is a 275x60x15, how did you get it in there with no rubbing? Thanks

[Jb427]

JB427, what size tire do you have on the rear 15x10 rim? If it is a 275x60x15, how did you get it in there with no rubbing? Thanks

I had magnums on before I redid my 66 fairlane 265 50 15 on 10x15s with 5 inch backspace I would have to lookback at exactly what order I did things but I never have any problem with rubbing When I put those wheels on I think every thing was std except for lowered rear springs but I did shorten std diff at one stage Now my springs are relocated 1inch new diff was made much shorter and I run American racing 15x10 with a 3.75 backspace on the rear same 265 50 15 tire. I think I could fit a 275 50 15 drag radial on the rear but they may rub

[6667fan]

My Magnum 500s are on car so can’t measure backspace. I believe the fronts are 3.5” BS. 225/60-15 np.
As far as out back goes you can run 255s with any number of back space combos. Soon as you try to put a 275 in there everything changes.

[c9zx]

JB, I mocked up a 255x60x15 rear tire on the 15x8, 4.50 BS wheel. I had 1" clearance to the spring and 7/16" to the fender lip. the 275 tire is 1.1" wider section width so, that is a no go with these wheels, that I am committed to using. Chuck

[Jb427]

*+

JB, I mocked up a 255x60x15 rear tire on the 15x8, 4.75 BS wheel. I had 1" clearance to the spring and 7/16" to the fender lip. the 275 tire is 1.1" wider section width so, that is a no go with these wheels, that I am committed to using. Chuck

Is that 1.1 inch wider with the tire fitted to the rim A few people run 275s here on 15x8s not sure if they rub. I took a tone of time fitting mine I was also lucky to have many offset rims borrowed from friends to try. for me it was the rear spring and on the outside there is the hump on the inner wheel tub it comes out to the quarter lip almost and it will rub up in there before it touches the lip.

Just have to find what your happy with. Magnums really suite a 66 67 fairlane or mercury

To fit 275s everything needs to be spot on. A 275 fitted to an 15x8 is around 10.8 inches wide

[c9zx]

JB, The dimensional data I'm using comes from the M/T website (Street ET, SS). I completely forgot about the "hump". I now recall the hump being a problem on my first Cyclone way back when. Thanks, Chuck

[Jb427]

make sure you post a photo once you got them fitted
Cheers JB

[c9zx]

It will be a few days, but I'll post pictures, once I figure it out. Chuck

[fryedaddy]

my stock suspension 66 comet will take a 24 inch tall tire-70 series,anything bigger rubs