<VV> Exhaust manifold question

[Geoffrey A Johnson]

Norm,
First try sandblasting, then soak as you have done.  Then double jam 
nut 
and try to remove.  If they break off you can try mig welding a nut to 
the broken stud and back it out that way.  Failing that, grind the 
stud so it is flush with surface of manifold, then drill out the 
stud with a small bit, then progressively increasing bit size to 5/16 and 
re-tap to 3/8-16.  Then install a set of  handy stainless 
studs with brass nuts from the vendors.  Even Ultra-folk wont go with 
anything less.

HTH
Geoff Johnson