Can you let me see a picture? Thinking
1. Get two Bushings, 3/8" OD x Whatever ID you can find like 1/8", 3/16"
2. Bang on the broken pieces with the flat punch
3. Clean, sandpaper, dry, Bushings and Head Surfaces with broken pieces
4. EPOXY the Bushings in place and allow to cure - good epoxy JBWeld etc.
5. Drill with Left Hand Bit
OR... Make your own Template. 1/4" flat steel bar, say 1-ft long, 1" wide...
Space out two 3/16" holes over the broken pieces, and two 3/8" holes, one on a bolt at the next port forward, one on a bolt at the port forward of that. Drill with a Drill Press so the 3/16" holes are SQUARE to the surface. Now you have a Template! Use thicker steel for more accurate drilling. You'll drill them out like a PRO.
Don't drill deeper than the inboard tip of the broken bolts. Seems there's a water passage behind at least some of the bolt holes.
