Aod stuck in gear starts in gear

Ok i've searched for similar problems but the search wont recognize aod for some reason. Anyway the problem is on an 88 LX 5.0. It turns over real hard in park and almost doesn't start. When you put it in neutral it starts fine but when jacked up the wheels move in park and neutral and all other gears. For some reason it stays in a forward gear all the time. Is the converter junk and locking up?? What could cause this? Anyone else have anything similar? Any fixes? THanks!!!

Well i talked my buddy into buying this car thinking that it was a simple linkage problem but we went through it and is isn't linkage. I have an extra stock aod laying around that i'll probably sell him. I'm thinking that the converter clutch is locked or something because it wants to go forward in park and neutral. Wierd!