I have a 700R4 tranny in my 86 Silverado, I just rebuilt the motor and I need a new torque convertor but the ones I've looked at say lockup or non-lockup and I don't really know the differance. How do you tell the differance? Also there is a plug on the drivers side with no wires coming out of it, what is it for and do I need to replace the plug and wires?