67 notchback resurrection

well may have screwed the pooch, while putting a bunch of the parts on. I got to looking at the water ports on the intake manifold........ decided to try to remove the vertical heater hose i believe fitting off and since it was corroded it snapped. Tried playing with fire for a lil and did not budge. Decided to start chiseling it to break the fitting inside, ended up buying a pipe thread extractor kit and well that didn't work out so well it dug in and ended up putting a crack in the manifold..... I really do not want to have to take it off and have it welded/fixed. Not sure if i just put some rtv on the new pipe nipple if that would seal it enough to not leak..... should have just bought a new one to begin with just had this blasted and powder coated before it was installed... If i do replace it does anyone have a good suggestion for a replacement nothing that is too outrageous in price?