Broke my water pump bolt. Now what? (Update - broken bolt is out)

I was given a 400 B engine that had 6 broken 5/16 and 3/8's bolts. The guy had tried everything and broke 4 'EZ' outs. He was told by so many to just toss the block and replace it. It was a 72 RoadRunner matching number block.

I grabbed 6 flat washers that fit over each bolt. I put some card paper under the washers, with a punched hole, to add just a bit stand off. I then turned my Wirefeed welder up to D heat and 6 wire feed (Lincoln SP155 240V). Welded the washers to the bolts. LOTS OF HEAT!
Let them cool down then using a 5/8's inch thread nut welded that to the washer and the center of the bolt. LOTS OF HEAT!

Rapped it with a hammer dozens of times.

Put my MAPP gas torch to it and got it CHERRY red again and rapped it again.

The Card paper will have burnt off by now. The stand off of the card paper allow some PB Buster to get to the threads and the shock of the hammer to work the threads. It also allows you to slightly tighten and loosen the nut back and forth.

Then used a 1/2 inch drive 'T' handle to turn all 6 out. Clean as a whistle. Ran a bottoming tap in the threads with some PB Buster just to make sure. Gave the block back to the guy.

SO, to the OP, just bring it to a GOOD race shop and they will have that out so quick.