Super Stock leaf springs

Same junk SS springs my neighbor has in his Barracuda. The ark of the spring is to large. You could use stepped shackles but the height of the car will be to high. Also check your pinion angle his is way off . The only thing you can do is have them de-arched or install the spring packs on your old main leafs.

For handling the more ark in the spring will affect the handling on corners. The greater the ark the more side movement of the rear on cornering. A flatter stiffer spring will prevent the side movement of the rear when cornering on the street.

Todds barracuda with the same springs were so high they have 1 inch blocks on top the springs to lower the car. Still when going into corners there is so much side roll movement the tires seem to be low on air. That is how bad the initial movement is.