So I busted out a valve cover bolt on my 3.9. I ran down to the hardware store and bought an extractor kit. I hastily commenced to drill but the bolt didn’t break clean. I didn’t take the time to smooth it out I just kept drilling like a savage. The bad news is I didn’t get the bolt out. Worse news is the hole now has a Mickey Mouse ear. It’s at least 5 threads deep. Is this something that can be repaired at a machine shop or am I going to be buying new heads?