[Z06vette]

I am assuming the car is mini tubbed. If you dont have the rear end yet, you can select the rim width/backspacing you like. Once tires are installed, mock them up in the wheelwells so there is equal clearance between the tire and the fender lip on the outside, and between the tire & the frame rail on the inside. Then measure the distance between the wheel mounting surfaces of each wheel. Now you have your rear end measurement, less the thickness of your rotors. For the front, need to know what suspension & brakes your are running.