In more depth whats a stall converter do and how it works

[91LX2Bfast]

Which brings up a good point:
If you have an auto equipped Mustang (or T-bird, wink-wink), you SHOULD be running an auxilary transmission cooler.
From a wise man: "Almost all clutch friction failures are due to heat. Put on a good external transmission cooler. The best type of cooler to run is the plate design, not the fin and tube type. Have to external cooler plumbed in after the cooler in the radiator.......For every 20 degrees of increase in transmission temperature over 170 F, the life of the fluid is cut in half......If manufacturers put good coolers on production cars, they would put most tranmission repair shops out of business."