Im surprised it re-tapped the 1st time, if the thread strips, that means the tapping drill size is over size... It wont retap again, without taking it out to the next size up or helicoiling. If it were me id be looking for a scrap engine and robbing the oil feed housing from it. As Graeme, points out slacken all bolt points, and get it threaded in a few threads and go from there