Trying to get info on wheel spacers for a 1982 Camaro Z28. Are these spacers
used on both the front and rear wheels? and what is the purpose of these
spacers. I have 15 inch rims on the car.

 

Spacers are used to correct problems with wheels that sit too deep in the wheel well, hitting the inner fenders or interfeering with brake calipers. Typical example would be putting 4th Gen F-Body or most Corvette wheels with their huge offsets on a 3rd Gen. If you select wheels with the correct offset, you won't need spacers.