I'm flattered I was mentioned!
I've been keeping up with this thread, but when it comes to mechanically related Mercury Cougar info, Royce is your man.
I'm more comfortable in the original marketing/advertising/racing history realm.
The Cougar Eliminator show car/prototype had a Dana-Spicer (Salisbury) two-speed rear end that was referred to as the "Streep" axle. Mercury even launched a "Streep Scene" marketing program for their performance cars in 1969.
The Streep axle never became a full fledged option and the whole Streep Scene marketing campaign didn't make it much past '69.
- Phillip