The SS springs were designed for drag racing, and teh leaves are oriented so that they're biased toward the front section of the spring to resist "wind-up" or deflection. The typical amount of ride height increase is around 1.5"-2" as they also have more arch. If you use the 002/003 springs, AKA "3,000-lb A-body", you'll find that the R/R will sit higher than the L/R. This can be avoided by using 2 of the same #, or adjusted out using the torsion bar height adjustment. A requirement with SS springs is to use a longer ("taller") rear shock, as the SS springs allow more chassis/axle separation. Imperial rear shocks, or old D100 ft shocks, are the cheapest way to go. The SS springs are pretty "lively", so on the street a shock with more control might be necessary to reduce the bouncing.