The block drain is about halfway between the cylinder head and the oil pan, so working from the bottom might help a little, not much. I'd suggest using spray brake cleaner or carb cleaner on the block around the plug, olus a wire brush to get any oil/grease residue out of the way, then heat it up as hot as you can get it with a Propane torch. If you have access to a MAPP gas torch, it will get a LOT hotter than Propane. I have done refrigeration system silver soldering with MAPP, something I can't do with regular Propane.
Jerry
