In the mid-1960's Ford started using a dark brown (almost black) colored friction material on their automatic transmission clutches. The stuff was hard as woodpecker lips, and without using a fluid with a lot of friction enhancers, the clutches would slip. GM used a softer, tan-colored clutch material that would grab OK without the extra friction additives. Pretty soon, the drag racers learned that using Type F fluid in a GM trans instead of Dexron gave it a much more positive shift, especially when combined with a "shift kit". It also had a habit of causing the GM clutch material to de-bond from the discs it was glued onto, but they didn't care- - - -the occasional hand-grenaded transmission was just part of playing the game. TCI (Torque Converters Incorporated) sold thousands of gallons of Type F to the racers by putting it in their own containers and advertising it as "high performance" transmission fluid. Good marketing to the P.T. Barnum crowd!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!