[scottj]

I've got '92 which is wider than yours by an inch front and rear, I think. You could calculate the difference to get your backspacing but I only have 1/8" tolerance.

Fronts are 275/40-17 on 10-1/2" w/8" backspacing (this retains zero scrub on an '88 and later front)
Rears are 335/35-17 on 12" w/8" backspacing.

You should be able to use 7-1/2" backspacing.

The sidewalls bulge out past the fenders which was acceptable to me, the alternative with the vette susp is a wheel with little or no dish.

Scott