Anybody Ever Seen an NOS "Formula "S" Exhaust System?? Now With Pics!!

To clarify for us "less than Ulf" readers, was the "Formula S" the same option as "Commando" and "HiPo"? Was it a term only used for Barracudas? It sounds like the dual exhaust was only for the rare Big Block engines (race only?). Those would have had a cut-out on the passenger side of the transmission support, which people do today to fit dual exhaust (TTI can mod. yours).

The AllPar site has a photo of a car showing the unique recess in the rear panel for the rectangular resonator. Besides the fender tag, that is about the only proof a car shipped with the Commando engine. I post a drawing from a FABO post showing the Commando exhaust discussed here. That Y-pipe looks a little hillbilly. Hard to believe a factory design, but I guess for low volume it made sense. My 2bbl Y-pipe is more elegant butt-welded pipes, but that required tooling. Real interesting that a single pipe made more power. I guess I won't be cutting my cross-member.