Valve cover stud stuck, need help!

[jam9297]

So I bought my first 300D a couple weeks ago, the paints in rough shape but everything else is in good condition. Now I know these old diesels are notorious for leaking(not a serious leak, just a drop here and there is all i'm saying). Anyways, this one had a visible leak from the gasket area and i'm guessing it wasn't taken care of very well by the PO(I made sure the cover and head were straight and they are). I figured I'd change the oil, adjust the valves and then lastly put on a new valve cover gasket and it'd be ready to cruise. I got through the first two things no problem, but when putting the valve cover back on, I noticed the rear valve cover stud closest to the passenger side was pretty badly stripped(the other 3 are good, but I did notice this one came off unusually easy and I figured it had to do with the low torque spec. for the nut but I guess not). I have tried vice grips, pb blaster, welding a nut on and using a socket to get it off(weld broke) etc. but these haven't worked yet. I'm unscrewing it CCW and the stud is most likely original since I managed to bend a pair of good locking pliers trying to unscrew it. I heated the stud up and bent the top over in an effort to give the pliers something better to grip onto(I used a heat shield to protect areas around the top of the stud) but I still wasn't able to unscrew it - the pliers gave way first. I'd hate to take this thing into a shop/dealer, but if they were presented with a situation like this, what do you think they would use to get this thing out? Thanks for the help/suggestions, -John