I make my own drain plug, really simple. 3/8 bolt and nut. I take a grinder and grind the six square sides off the nut until it is round. Drill a hole in the pan where the factory would have the drain plug. The rounded nut on the inside, a 3/8 bolt (3/4 inch long) bolted through the hole. Tighten down and then weld the rounded nut to the inside of the pan. take the bolt out, use a copper washer for the 3/8 bolt and you are done. Simple, costs about 50 cents.