I tried JB Weld, didn't work.

I tried some other crap today, not looking so hot either. I am worried the patch will fail while boating, spray gas on the hot headers and not end nicely.
I did see the replacement bowl also, it is one of the front plugs leaking, so that would work, just afraid one of the rears will start leaking and be in same boat...no pun intended.

If the other bowls worked it would eliminate those beautiful plugs...
What holds those plugs in and how do you get them out? I like the tapping idea. didn't think of that. (edit: dumb question, drill em out right?)