Yes I believe if you ordered from the factory a/c the vehicle would come with the 340 torsion bars and even the 5.5" wide steel wheels, even if only a /6 engine.
Bennoel 10, you are incorrect. I had a 69 Dart Custom with AC. Wheels were 4.5, I believe, and the Torsion were also lighter. The wheels I pitched years ago, but kept the bars in case I were to put together a SB drag car.