Hot Rods School me on 39-48 drums and hubs

Ok I know the basics that the early hubs are inside the drum and the later hubs are outside but can you mount the late hubs inside the drums? I presume the later hubs and drums bolt right on with the earlier backing plates. I want to get some Lincoln style drums and I only have the later hubs so I'd like to know where I need to go from here

Gotit

 

'39 drums are wide 5, '39 uses same drums as '37 and '38.

 

True. Wasn't thinking about hubs but more the backing plates but I'm asking about the hubs. Thank you