hogflyer

I don't recall off hand what the chemical is, but there is a chemical you can put the parts in that will dissolve the drill bit (or any ferris material) and not hurt the aluminum. May be worth doing a search on the net for it. There was a guy on a Mopar forum who had to extract a broken tap from an aluminum head and it was suggested to do this. He said it worked after soaking for a few days or so.

Hogflyer