Pelican Parts Forums - Any Suggestions on this problem?

So after several delays, I finally got my motor mounted up on a stand, and torn down sufficiently to gain real access to the exhaust studs I broke a few weeks weeks ago.

The first stud I started in on did not go so well. Penetrating oil has been on all the studs for a good while at this point, and I heated it with MAPP gas for several minutes before making the attempt. It almost immediately broke off flush with the head. Undeterred, I began drilling the stud out (see the third picture). Keep in mind at this point I really thought that I had a chance at extracting this thing. Of course the hole was slightly off center, but I pushed on, and slowly made the hole big enough to get an ez out in it. I felt as though I had made the hole as big as I safely could without hitting the threads on the side. So I reheated the aluminum, and cranked on the EZ out, and got nowhere.

So where do I go from here? I am leaning toward removing the heads and taking them to a machine shop. Is there another way out?

Also, after closely inspecting the rest of the studs, they all look they should be pulled and replaced.

Apologies in advance for the rant. I'm in need of some emotional support here...

The pictures:

http://forums.pelicanparts.com/uploa...1365128270.jpg
http://forums.pelicanparts.com/uploa...1365128297.jpg
http://forums.pelicanparts.com/uploa...1365128309.jpg