What is the recommended offset for the right rear torsion arm on a DRC?

Drc 317-481-1626.

I have that number. Can you get them to answer?

Just off the top of my head, I think for any chassis..

Center the rear end in the car, while up on setup blocks.
Install the bird cages and snug them up with spacers and wheel nuts.
Install the torsion bars without stops or arms.

Measure from the center of the chassis to where the center of the arm would be on the torsion bar.

Measure from the center of the rear end out to the center of the bottom bolt in the bird cage.
(the center of the bolt along it's length, where the arm heim would go)

Subtract one from the other and that would be your offset.