If they are early 50's car stuff they will work.
You'll end up using the truck inner bearing and the car outer, or maybe its the other way around, its been a while since I last did this.
You may need to redrill the holes in the backing plates to fit the axle, and you'll need to space the backing plates (very securely!) to make sure the shoes are located correctly to fit the drums. Keep the spacers you remove as you remove the stock backing plates, and use them as a pattern for diameter and thickness and then measure to determine the correct length.