What the diffence between a high stall and med stall torque converter

The difference is the RPM at which the transmission will engage. A high stall will engage at a higher RPM. This will give you more abrupt acceleration.

Stall is also relative to the torque output of the engine and the RPM range of the torque. The higher the torque, the higher the stall if it peaks within the range of the converter. A custom converter designer will ask all kinds of questions about cam profile, gear ratios, rod length, bore, stroke and other engine modifications. At that point they can design a converter for your specific application and accurately predict the stall speed. For example, the converter in my Cuda was built to the specs of the car. It is a 4000 rpm unit and actually flashes on the launch at just uner 4000. Once driveshaft speed increases, engine speed increases accordingly as well. However, when driving on the street it is also designed to stall lower based on partial power input and is very docile. Whack the throttle and the car gets extremely aggressive very quickly. Now, to answer your question, a medium stall will flash at a lower rpm than a high stall. What astech said above is true. If properly matched to the power train, a custom TC will multiply engine torque through the transmission for quicker starts and faster accelleration. However, if too high a stall is applied, the vehicle will be lazy and the transmission will only run hot. In most truck applications a lower stall converter is better for trailer pulling and off road low rpm torque and performance. Hope this info in helpful!