Actually it is in the exhaust flange at the bottom of the manifold. I soaked it in everything I could find for three weeks, put vice grips on the stub, tapped on the stud for hours, finally drilled the center and put an ez-out into it only to break the tap handle in three places.
Now I have rounded the hole and don't know if I can drill all the way thru into the exhaust chamber after/under the flapper.
a) Can I drill into the chamber, and if so do I worry about the chips falling into the manifold?
b) Can heli-coil or Tyme Certs be used in cast Iron?
c) Do I have to replace the entire manifold, or does the plate that has four bolts on it come off?
I just wish to avoid any more damage.
