Were it Me,Chuck the orig system.
I would just buy the 2 cab floor supports and weld them in.
Get a set of rear shackle mounts from whomever,use the Kit You already have to rebuild them and bolt them up.
Last thing to do would be to Make Sure the truck is DEAD LEVEL and with the floor being at the correct clearance to the frame,push the drop leg of the bracket against the frame rail and drill the 4 holes,2 each side.
Retro,ed to a 5 point system!
regards,
steve sr.
Last edited by steve sr; 05/02/2016 6:09 AM. Reason: info