Exhaust stud removal

["schab932000" <schab932000@xxxx>]

I need some advise. I'm replacing the exhaust mainifold gaskets 
and everything was going okay, until it came time to remove the 
studs. I have standard vice grips which do nothing other than 
slipping around the stud. I went to Sears and Auto Zone to look 
for another type of wrench but found nothing. I've also heated the 
studs and used plenty of liquid wrench, but not luck. Any ideas?

Pat
vin 5552