we used to fix em by cutting a hole in the top of the head so you can weld them from the back of the crack,,,inside the water jacket,,,the problem with cast welding is the awsome amount of pourosity that "can" occur & allways seems to come to the top of the weld & obviously not where you want it to be pourous...so by welding from behind, the pourosity doesn`t bother the hard weld area where you want it all clean,,,if you get my drift, then just weld the plug back into the top of the head, easy-peasy

still a tough job & yeah as the good Doc says,,,heat it up,,,weld it,,,slow heat cool it back down & then re-shave the thing from the massive warp you`ve just created by the heat factor
& the loose bung thing???...welll...another eay one,,,i pull the old plug out,,,thread the hole,,,make up cast iron taper threaded plugs, screw em in with locktite & shave it, sweet as a nut & never ever have another problem with it again,,,easy-peasy
i hate brass plugs in cyl heads, what a pain!!!!! & whoever decided to design such a silly bloody concept aught to be shot!

cheap asred bloody pohms!!!
