The switch pitch that Jerry is talking about requires a switch on the throttle or the dash to switch the converter veins from a low stall to a stall speed, I ran one in my race car for years with a simple push button. The second wire is the kick down switch, again from a throttle activated switch. If the transmission has more wires then this, It's not a T400. The 400 is a simple to install unit, no electronics required, they will run with out any inputs, it just won't shift as hard or as high in the rpm range, but it will live just fine. The 400 also has no cable to attach to the carburetor.
