I'm face with that probleme each day:
http://www.benplace.com/head3/100_0007.jpg
http://www.benplace.com/head3/100_0007.jpg
http://www.benplace.com/gilles/gilles3.jpg

You have a few choice but be carefull. First thing to know, if you heat that
thing up a lot and use cold water a few time the stud will harden and there
is no way you will be able to drill in it! So, the best way it to "mig" weld
a nuts on the remaining threads, use cold water to cool down, heat up that
thing with a torch and cool it down a few time... poor cold water on it! go
for a try. BUT, like i sayd, if you break the remainning stup flush with the
head... your are cooked!!!! You won't be able to drill in it.

Ben

On Fri, 10 Aug 2007 09:23:35 -0300, Tom Rowsell <tom@GEOEXPLOITS.COM> wrote:

>Ok I might as well advertise my stupidity to the list: While removing the 8
>exhaust bolts from the heads, I was only successful in extracting 7. I
>twisted the last one off...got too confident/aggressive I guess. So, I'm up
>on blocks with no exhaust, and about 1/2" of bolt sticking out of the
>exhaust port. It's the upper one on the front, drivers side. I'm hesitant to
>do much else, lest I break off the last bit. I'll probably get it towed to
>someone competent, but would like to hear from some "advisors"  :)
>
>Thanks
>Tom
>http://tomrowsell.com