Bingo! It fits in the lower radiator hose, and cools the transmission fluid by circulating the coolant around a coil of tubing inside. The fluids don't mix, the coolant just cools (or heats)the tranny fluid. The Powerglide makes a lot of heat, especially when the torque converter is assisting engine torque during breakaway from a stop.
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!