OK so I managed to drill out 2 broken exhaust manifold studs head in. I kissed my Blue point right angle drill and a new set of high end drill bits i bought. I had to drill them out larger and re-thread to 3/8X16 and get new studs. Not totally done but almost.
Question. ALl of the holes in the manifold where about 7/16 diameter except for one . 3rd cylinder upper hole was about 5/16. quite tight. Because I oversized the new studs I had less wiggle room making it very hard to re-align. I had to remove and drill out slightly larger to accomodate my change. Is this normal that the upr 3rd cylinder ex-manifold bolt hole is smaller than the rest? Sure looked original....