Swapping in a 383 and broke an exhaust manifold bolt in the head (cast iron heads). It is the front bolt on drivers side. Broke off flush with the head. I drilled through the bolt and tried an extracter and busted it inside. Now the extracter is too hard to drill into. Also tried to weld broken bolt to washer and then attach another bolt to remove, but the extracter material is Fu**** up the weld and can't get it to hold. Ruined my day and now my weekend-help- what can I try next? Who may be able to fix it? Will I have to remove the head?