Technical '39 Mercury-Changing Lug Pattern

I picked up a '39 Mercury sedan that will be going through some mild changes. 283 to the original 3 speed to the banjo rear. I would like to use rims with the Ford 5 on 5 1/2" pattern but the car currently has original wide 5 rims. I have the bearings to switch to a set of complete '56 F100 front brakes (I'm assuming the '39 Ford and Mercury used the same spindles). My question is how to switch the rears. Can I remove the wide 5 drums, backing plates and hubs and simply use a set the would be for '40-'48? The idea of swapping to a '40 rear seems to get complicated because the Merc's torque and driveshaft are longer than the Ford's and I believe the Merc has a one piece pinion/driveshaft, not coupled like a Ford. The car is a 4 door sedan but is really kind of growing on me as a great high school car from the '60s. Should be fun!

 

Just change the brake drum to 40 style

 

Yep what he said all you need to do is change the drums and hubs

 

thanks for the quick responses, that's kind of what I was thinking.