George I never made any comments about plugs for cast iron. No ear broke off. The threaded boss pulled off and I don't know why. There is no gasket. There are 2 O-rings that seal the oil ports into the oil cooler. I can only guess that maybe I had the bolt a little tight and when the oil cooler got hot it expanded some and caused the break. It certainly didn't break when I tightened the bolt and wasn't leaking at first. I listed the other rod because it is similar to the the ones yomax4 suggested. That's why I had his name at the beginning of the paragraph. I think it's part of the block and I can't put a whole lot of heat to it without removing the injection pump and a whole lot of other parts. If it is separate, I'll take it off and braze it.