28X10.5 tire on 1979 Aspen

[Aspen79]

has any one ran A 28X10.5 slick on 79 Aspen. What modifications did you do?

 

[MiradaMegacab]

I ran a 30"X10.5 on a Mirada, I did move the rear axle (B Body 8.75) back, maybe 1.5". I used the forward hole in the axle perch and drilled a new hole in the shock plate, that mounts below the leaf springs... The clearance issues I had were the leading edge of the inner wheel well and the tire to leaf spring......

 

[CM360]

A 41/2 BS wheel easily fit a 29" tall 9 " slick.I believe a 10.5 will fit with some trimming.

 

[AJ/FormS]

I put 275/60-15s on a 1980 Volare;no mods.Those are 28 tall x about 10.8section on 8.5rims. No airshocks either lol.....Slanty car

 

[Aspen79]

I put 275/60-15s on a 1980 Volare;no mods.Those are 28 tall x about 10.8section on 8.5rims. No airshocks either lol.....Slanty car

Any pics

 

[AJ/FormS]

Tires long ago wore out. It currently has 255/60-15s,IIRC. These are about 27 tall.

 

[Dr Lebaron]

I have 275/60/15 on Mirada wheels out back on my 79 Lebaron with no issues, unless I get into serious autocross, then the might be a problem.

I could go even wider, but with stock Mopar wheels, all out of offset.
Then a 8 inch rim would be better than a 7.

 

[7T8 Custom]

Any idea what the max width you can go with a supercoupe wheel (15 x 8 with 4.5" offset) without rubbing. I was thinking 275/60R15 but would go wider if they will fit.

 

[Dr Lebaron]

4.5 offset is the limiter on width due to the leaf springs.
275 is as big as I can go.

 

[BudW]

Dr Lebaron, Do you have a picture(s) of your 275's and their relation to the leaf springs?

Also, are you using a 7¼” or 8¼” differential, or something else?
If something else, what is it from?

I will be looking for tires/wheels very soon, and inquiring minds want to know (no extra spending $ on my end, for testing purposes)

Thank you,
BudW

 

[kkritsilas]

Sorry to be pedantic, but the measurements that people are calling offsets are actually back spacing. Back spacing is the diffeence from the inside edge of the rim (without the bead) and the mounting surface of the wheel. Offset is the difference between the same surface and the middle of the wheel width. On an 8" wide wheel, you can have a 4"back spacing, and the offset is 0. On the same wheel, a 4 1/2" backspacing is a +1/2" offset.

 

[BudW]

. . . Back spacing is the difference from the inside edge of the rim (without the bead) and the mounting surface of the wheel. Offset is the difference between the same surface and the middle of the wheel width. On an 8" wide wheel, you can have a 4"back spacing, and the offset is 0. On the same wheel, a 4 1/2" backspacing is a +1/2" offset.

He is correct.

I knew what was being said above and wasn't going to correct them, but sense you brought it up, I'll join the bandwagon.

It is easy to misuse those terms

 

[F body Deconstructor Jim]

10.5x28x15 with a B body 8.75

 

[9secRR]

28/9/15

 

[9secRR]

many years ago, 275/60/15

 

[9secRR]

275/60/15

 

[BudW]

10.5x28x15 with a B body 8.75

Jim, do you know what year B-body 8-3/4" differential

 

[BudW]

28/9/15

I wasn't sure what you were trying to say in this post, 79410aspenrt?

Was it 28" x 9" on 15's?

 

[9secRR]

yes 28'' by 9'' on 15'' rims.

 

[F body Deconstructor Jim]

Jim, do you know what year B-body 8-3/4" differential

Not sure Bud, prob a 70 or so. I'll get the specs on it once its out.
My notes say the wheels are 15"x10" with 5" backspace.