how do you use them? i really got no idea, say you get a 3000rpm stallie can u stilll let it out at say 2500rpm?

OK, worth reading up on torque converters in general:

http://auto.howstuffworks.com/torque-converter.htm

A "High stall" converter simply changes the point at which the converter is said to have reached "stall" i.e. basically when the impellor and turbine reach the same speed and the stator begins to freewheel (as its on a one way clutch).

The standard stall speed on e series falcons is around 1900rpm.