Why not go with a parallel 4 bar with the mounts on the outside of the frame rails and a Watts linkage???? Parallel bars about 24" long bolt to bolt with a Watts linkage with the center bracket attached to the rear end with 4 or 6 bolts in the rear cover and a bar to either frame rail would be very good at hooking the car up, and look good too!!!!!

A triangulated 4 bar with arms too short and not angle properly can bind up terribly and do some nasty loading and unloading of the chassis torque making for lousy handling and a bad ride. Yes, the center section is a cast piece....