1968 C-30 Stepside Wheels/Size

[Troy.Blackburn]

Does anyone know if wheels from a 2011 2500HD will fit a 1968 C-30 Stepside? If not or if you don’t know, does anyone know what backspacing/offset I should opt for? I’d prefer to get 17” wheels.

Thank You
Troy

[Mike C]

On my '70 GMC C2500 I ran 265 75 16 on 16x7 Alcoas that had 4" backspacing (zero offset) and that was a great combo.

A 17x8 with 4.5" backspacing and 265 70 17 should be a good fit on your truck as well.

[Troy.Blackburn]

Originally Posted by Mike C

On my '70 GMC C2500 I ran 265 75 16 on 16x7 Alcoas that had 4" backspacing (zero offset) and that was a great combo.

A 17x8 with 4.5" backspacing and 265 70 17 should be a good fit on your truck as well.

Would the 17x8 also be a zero offset?

Thank You
Troy

[Mike C]

Yes. An 8" wide rim is measured between the beads on the wheel so an 8" rim is really 9" overall width so the distance from the centerline mounting surface to the back of the wheel is 4.5". Same math applies to the 7" wide wheel as well. Overall width of wheel is 8" distance to WMS is 4".

[Troy.Blackburn]

Ok then, so a 4.5” backspacing is going to move the inside of the wheel/tire 1/2” closer to any potential interference. Based on the clearances you have on your truck, do you feel that will not be an issue?

Thanks Again
Troy

[Mike C]

I don’t think it would be a problem. It moves the inside in, but it also moves the outside out.

To answer your original question, the OEM 8 lug rims will fit up until 2010, but they have even more backspacing. I want to say 4.5” on a 6.5” wide wheel? Google would answer that question for you.

I still think the 7” rim with th 265 tire is a good fit for one of these 8 lug trucks.

[1968k20]

Is the c30 a dually?

[Troy.Blackburn]

Originally Posted by 1968k20

Is the c30 a dually?

It’s a Stepside, so it’s a single rear wheel.