Another engine ID issue

[Prawbly]

I bought a 36 Tudor with what I was told a 48 59AB. I've bought parts for the 59AB and they all fit okay. I finally got time to pull the engine for detailing and cleaning and there wasn't a thing on the bell housing. Now I don't know what I got. LoL !! The engine runs great I just wanted to clean it up. What can I look for to identify the engine? Are there specific dates they didn't put the numbers on the bellhousing ? I would just like to know what engine this is. Thanks Pat