If you look at the angle of your shackle it is almost straight up and down. For best ride they should angle forward about 20 degrees. This will also help flex by allowing more droop. The only way to change this angle is to move the upper shackle mounts forward or use a spring that is slightly longer behind the axle. Using a longer spring require boomerang type shackle to keep it from hitting the body when the spring compresses. Poly bushings will pivot easier and help the shackle move easier. Just changing to a boomerang type shackle won't be any different than a straight shackle of the same length. Angle is determined by drawing a straight line from the center of each mounting bolt. A longer shackle will pivot easier and help slightly with ride quality. Other than that softer springs or shocks with softer valving is the other way to improve ride quality.