84vetting

On a 84 Vette with stock wheels , anyone know the backspacing on the rear wheels, I know they are 16x 8.5 , just need backspacing in inches

WVZR-1

an 8 1/2 is thought to be 6" +/- very little

a 9 1/2 is thought to be 6.7" +/- very little.

If you've doubts "MEASURE"!!

hcbph

I didn't measure, but 8.5" should be +32mm backspace and 9.5" should be +38 mm backspace. Should be molded into the backside of the rims. WVZR-1 is most likely right on measurements in inches, don't think I've seen bad data so far from him.

WVZR-1

Bad DATA? You notice I also mentioned "thought to be"!

Well let's consider the math! You first need to measure "Total Wheel Width" - A very general assumption is that TWW is the advertised width +1". So 8.5 +1 = 9.5 / 2 = 4.75 + 1.259 (offset) = 6.009 The math for a 9.5 should yield maybe 6.746 - round up or down?

Back-spacing when used in tire/wheel fitment needs to be calculated measuring by the user. It certainly be different wheel to wheel.

Hot Rod Roy

We're confusing "backspace" and "offset" here. "Backspace" is the distance from the wheel mounting surface to the back surface of the wheel, with a straightedge placed across the back of the wheel. "Offset" is the distance from the wheel mounting surface to the centerline of the wheel.