Late last year, I started developing an exhaust leak from the number 6 port which was... of course, broken off flush with the head. Probably has been broken for many years before I got the car. With the nice summer weather, I decided to replace the gasket & install all new high grade studs & bolts. Let PB Blaster go to work for a few days and went to work. I removed the manifolds and used left hand drill bits to extract the broken studs. (number 1 was also broken off - discovered whe