Bypass nipple on the underside of the head is broken off flush. Tried WD40, heat and "easy" out with 4 foot cheater to no avail. Anyone know what the thread is on the nipple? Seems to be sort of 5/8 but with a thread between fine and regular. If I can find the right thread chaser I can drill and clean out the threads. Otherwise, any good ideas on how to seal it? Weld patch, bash in a copper or brass plug?...... :madder: