The reason being of 5 degrees up is the way the springs fit to the hanger mounts. The spring is designed to be relatively flat and the front eye is lower than the back mount, like a jacked up car looks, a straight spring holds the car better in corners. The S/S springs with big arch is for drag racing only. One thing about the SS spring, never weld both perchs where they sit on the spring. Tack one side then remove housing then tack other at same degree, re check your measurements and weld up. Then when bolting the u-bolts one side will pull the spring up to set the spring preload Chrysler engineers designed into them.