I got a question for you guys, me and my buddy was debating over my dinner birthday tonight. Which leaf spring sits higher on the SS leaf springs, left or right? And can't you use two left or two right on the same car?
The right side sits higher on the SS springs... Unless you installed them on the wrong side....
Due to the rotation of the driveshaft and the gearing in the axle, the right side sees more torque than the left. That's why the factory B & E bodies had stiffer right springs than the left. Under hard acceleration, if you don't have a stiffer spring, the car was found to jump almost a full lane to the right. Therefore they had to make the right hand springs stiffer to handle this condition for safety.
Theoretically you could put "equal" springs on both sides, if you don't plan to drive it very hard. But if you are putting out over 300 hp and plan to get on it hard or drag race it, the stiffer right spring is the safe way to go.