GTsvt

I have a 1996 cobra, and i was flushing out the coolant system. On the cobras you pore the coolant right into the block and radiator through a part called the (engine coolant outlet tube). Well the plug that tightens on it was still factory sealed, and i stipped the plug. Does anybody know where to get a new plug?? Just the plug(part that screws on)

thanks for all replys