Converting rear drum brakes from SBP to BBP

I appreciate all the replies .... moving forward , it looks like i will be easier if i switch over to big bolt pattern backing plates and drums... i do know i have 76 volare setup ... my NEW question is that i will need to redo my steelies ... i will have stockton make me new 15 X7 steelies ... any of you can tell me after installing new moser axles ( being there longer ).. what offset did you use on steelies ?

Thanks