Oil for 3-speed?

I double checked the service manual and did some online research, and it all said that trans. uses ATF. I just changed to Dexron III...It's easy to change with the filler plug on the bottom. I don't notice any difference in shifting or noise. I think gear oil would be equally acceptable.

My other problem is that it's forcing oil from somewhere when the car's moving. The vent makes sense, but it seems dry up there. There's a chance it could be blowing it back so it doesn't land on the top of the trans, but leaks down the side. It's definitely coming from up high. My local trans guy put front and rear seals in it and used RTV for the top cover. It could be coming from the tailshaft to main body gasket. Who knows, but finding parts for this thing is a bummer! Good luck with yours!