A converter is a torque multiplier and will let the car get to the rpm level that is in the torque curve to provide greater launches. Picking a converter should be left to a converter shop and they will need lots of information to better pick a stall speed that suits your situation such as rear end gear, weight of vehicle, motor horsepower and torque, and size of tires. As I posted earlier I have been through this before and if the wrong converter is in place it seems as though the car has no power off the line and has to fight, so to speak, until it gains enough rpms. I have purchased from West Coast Converters and have been pleased wi the service and product. wcc@westcoastconverter.com