Mopar leaf-spring suspensions are ... which can be tuned in with Mopar's P4529536 steel shims. The initial setup used P3412002 and P3412003 Super Stock springs and Mopar P4529517 drag shocks.

remove the four spring seat U-bolt nuts and install new nuts, part No. 08911-6441A, finger tight. Using a pry bar, separate the spring pad from the leaf spring to make room for the shim installation.