[PMDRACER]

I run 28x10.5-15 Stiff sidewall M/T slicks on my '71 with Ralley IIs.

I had the Ralleys modified to 8", but I split the difference. 1/2 inch inboard, 1/2 inch outboard. "Stock backspace + 1/2".

It's a little close to the lip of the quarterpanel, but I also run rear discs, and that pushes the rims out an extra 1/8 inch.

I could easilly get another set of Ralleys made to a 9" width, putting 1/2 inch outboard and 1-1/2 inches inboard.

Remember that the width of the rim won't change the tire width that much unless you have a 10.5 tire on a 6 or 7 inch rim, then it will suck the sidewalls in and reduce the usefullness of the slick. You have to look at where the tire will sit in the wheelwell, figure out the relationship of the axle flange to the centerline of the tire, and set your backspace accordingly.