I liked the possibility that a bushing is stuck on the pivot bolt, so it is currently soaking in liquid wrench. All of the engine bolts had been removed. I had already tried alternately turning the bolt and banging with a hammer. The dogbones had been loosened, but didn't seem to make any difference. The swingarm seems pretty solid and the bearings may be OK, but I need to get the engine off. I have just the frame, swingarm, and engine right now. After the liquid wrench treatment, I'll go at it with a big hammer again. If that doesn't work it will either be a dremel tool on the bolt head (so that I can go the other direction) or sawz-all where ever I might access the bolt through a gap in the swingarm-frame-engine. Thanks for all your help. I'll update when it is resolved.