Do you have a "screw knocker"? No B.S., this is a real tool and one of the best tools in my tool box. Found out about it from a Willys Jeep guru on one of the other web sites a few years ago (he happens to be an aircraft engineer). The tool was developed for the aircraft industry to remove stubborn rivets when making repairs to airplanes and jets. It's an attachment for an air hammer that has a 3/8" drive shaft with 5/8" box end wrench attached to it. You put it in an air hammer, put the socket/torx bit/whatever on, insert the bit into/on the bolt, and squeeze the trigger. The air hammer vibrates the crap out of the bolt/screw and you use the 5/8" wrench to turn the socket with the other hand.
I have had only one bolt that this thing did not budge.
You can get one from Brown Tool Company.
Richard