[V8] Timing Belt-Carlisle is slipping away

[Lanier Pratt]

Ok guys.  Tony and Ron have been amazing help.  I have now hit a  
snag.  While attempting to take out the very last 12mm bolt that is  
left in the passenger side timing belt cover I stripped it.  I've had  
a few suggestions thus far including grinding a flat head slot in the  
bolt to be removed with a slotted screw driver or simply grind off  
the bolt head.  Any other ideas before I proceed to do damage to the  
bolt?

Lanier Pratt
'92 V8Q 4.2L
'90 V8Q 3.6L