Really have a Pandora's box....here....

Started with a Temp sender not working on 86 2.1L...diagnosed no continuity
(ground) between the aluminum thermostat/temp sender housing and the head.
Thought I'd just remove the housing, clean up the bolt threads and re-
install...

Bolts would not come out.....both frozen and sheered off in the head.
While trying to back out the bolts by drilling and using an easy-out, I
cracked  the aluminum head with the easy-out at the upper bolt hole. Pretty
big crack at the top of the bolt hole/thermostat mount.

Anyone have any luck tig welding on Vanagon heads???

Opinions?....will I be able to weld/repair this head or will have have to
put on another head.

Warren C.