I have a 1:16 torro metal chassis but the gear box that came with it doesn't connect to the TK7.0 MFU for my Leopard 2A6, is there any wires I can get or do I take out the Torro gearbox and put my Original Steel Gearbox inside? I heard Torro Gearboxes are good which is why I wanna see if I can use it.

Just change the wires to the type with the correct plug.
you will have to remove the transmissions to solder the wires off and onto the motors.