When I push down on the back of the truck it doesn't rise back up very fast. It always seems like its sagging with the body on. it seems like the back tires hit the body almost. So I would assume I need stiffer shock springs. I have the factory ones on which are single yellow on back and single white on front. Which ones would I need to stiffen up the back?
Orange and Green stripe are the next two stiffer springs than stock. There is a chart in the manual with spring rates and color codes. The white ones in the front are actually stiffer than the Yellow. You might just try swapping them and see what happens before you buy anything.
The Super Derecho