My son says Its my answer to everything.
2000 Cheby 5.3 V8 Aluminum heads. Last manifold broken off below the surface of the head.
I used Alstate 275 at 71 amps I built a little tit on it, then another one,..... Till I could put a 3/8" nut on it. I welded the tit to the nut and took it out after it cooled. The one next to it only had the head broken off, so I took that one out too.
Through this hole.
My lucky day. I made good $ on it too.