New spring install?

our 71 Duster with the 002/003 SS spring is in the Acceptable Position..that is as far as I can get them to go back.....

I saw a picture where someone made a spacer that goes between the frame and shackle mount...which in effects moves the angle back....

This Duster is used for bracket racing and generally 60 fts 1.590 to 1.62....so I dont think it is really having an effect on the car hooking.