[DeTomaso] Galled stainless fasteners

[Dave Londry]

Has anybody got particular experience with galled stainless?

I got #6143 with a fancy Gilmer drive with black stainless pulleys, an 
aluminum waterpump
 and black-stainless bracketing for the alternator and A/C.
I just went to whip the front cover off to get my wiped camshaft out and 
found the morons used
stainless fasteners (304 I imagine) and no anti-seize.
I have all but 2 of the necessary ones our now, but one of the remaining 
ones was the first one I touched.
Of course it's a hex-drive and I stripped it. I've had a torch on them 
and been dosing them with liquid wrench,
 but no luck. I don't see that penetrants are much use for galling anyway.
The round head is 9/16" and I can't find a stud extractor that big so 
all I can think of is a 9/16 bolt extractor.
(fits over the head and has teeth) and an impact wrench..
I imagine I'll eventually tear the head off and then I can use my stud 
extractor on the stub until I twist it off, etc. etc.

Any ideas welcome.
thanks in advance
dave