thanks to all who piped me quick advice (terry, tim, derek, cory, larry,
and mark), including steve schwenk who i spoke with on the phone.

liquid wrench is my friend.  i will be buying the gallon can at osh next
trip, for i see it has extremely high use value.

it took three sets of lw application, banging with a 4 lb sledgehammer,
plus torquing with a combo wrench again and again and again for the front
differential bolts to even begin to turn *with* the nuts.  then one more
application each side, plus some judicious sledging using a flat punch, and
the combo wrench and a small crescent (as a wedged stop) working hard, and
i got that satisfying "crack" when the threads broke free.  ten minutes
later i had a prop shaft in my basement and no more vibration at 35mph.

thanks again, all.  rule of the day?  read bentley *properly*.

bill
'87 syncro westfalia
http://www.scruznet.com/~cikasper/pics/westy