Really, as long as you have a good spring rate in the rear, it doesn't really matter. i.e. - a super stiff pro touring type spring in the rear will be bad for racing at the track... but so would a super heavy rate coil over spring. But if you have, say a Moog 6 cylinder rear spring in there and your ride height is good, it will work just fine... and so would the correct rear spring rate in a coil over spring. The main thing is a good rear shock and a light enough spring to let it hit the tire. The main benefit of going coil-over is ride height adjustment and tuneability.
