They have a version that has a custom short torsion bar in the tubing that runs parallel to the frame. Pretty interesting. Uses a non coil over shock in the stock location but moves the torsions for clearance and weight. He doesn't have it on his website (at least the last time I looked....). There are some pictures on Big Block Dart if you search. IIRC, it's over 6 grand for that version. He originally built a torsion bar version for the Viper Challenger he helped build for the car builder Delaney.
Wes