Back into the tranny, like if you have a few metal chips and stuff and it gets back flushed you can have that in yout clutchpacks and gears in the converter.

 

disconnect tranny cooler line quik coupler near rad, keep a gallon handy, start unit , in neutral flud will drain and when a gallon has drained pour in the new gallon and let drain until it stops flowing, shut her down, now you have accomplished 2 things, flushed torq conv and drained fluid level in pan to near sump level, highly recommended after having removed pan is to adjust bands , also replace filter.
Marc

 

Definetly flush it, not just drain the pan. Draining the pan only gets about 75% of the fluid that is in the system (the rest is still in the lines, torq converter, etc...) Flushing it is the only way to ensure you get as much of the fluid as possible.