Auto tranny questions...

[Tee]

I'm reading the Haynes manual on GM trannies because I wanted to learn about Automatic transmissions. I had a few questions though: 1) how does a booster valve work? 2) What is generally meant by a shift kit? I've completely read each post in the tranny section and learned quite a bit. I would really appreciate if someone could help me with these two questions I've posted. Thanks all!
Regards,
Tee

[FastGT31]

i dont kno wwhat the booster valve is but a shift kit raises the lines pressure through either replacing check balls, relocating them, or new plates for the valve body. with the pressure up, the trans will execute a shift much harder and faster than without it. its good for racing in that it wont allow soft shifts which could damage the trans with enough power.