Not sure if it was a Cossie, but it would not be hard to imagine.

The whole idea of the dealer Supercar (Yenko, Royal, Tasca) was to work with what was basically already there and level up what the Detroit marketers were reluctant to release. That is the idea of the COPO, or the Service Department swap. If it could be bolted on, painted on or built in at some point, it was fair game.

Going through entire drivetrains, etc, was expensive and costly - that would take them from franchised dealers to specialty automakers.

That is a much steeper hill to climb when doing it on your own nickel. .