Monkbonk, if you don't get that drum loose then make a post over in the driveline forum for some tips on getting it off....especially since the shoe is probably stuck to the drum.
Idea's like, hit it a few time with a hammer to perhaps shock it loose.... make sure you back the shoes off as much as you can...and a few more tips the guys can give you. Good luck.
If you do not have a repair manual yet you may want to take a peek here at the online manuals.
http://chevy.oldcarmanualproject.com/
