1972 axle 1969 truck

[~Whitey~]

Hey all I'm a newbie here and need a little help. I have a 69 short wheel base 2wd with a 12bolt rear 6lug. The truck has drum brakes all the way around. I purchase a 72 long bed 2wd as a donor vehicle, it's 5 lug. I understand how to swap out the fronts so I'll have disc brakes on the front of the 69 while at the same time converting it to 5 lug. However on the rear, I know I can't just swap axles because the 72 is roughly 2 inches wider drum to drum and the bearing will ride in the wrong spot. What I'm asking is... what if I just swap the entire axle assembly, is there any downfall to that? Seems the rear being a bit wider would be better, not to mention the bigger drums would be beneficial as well?? I know there is a kit to convert the rear to 5 lug; but swapping assemblies would be cheaper for me since I have the complete 72 rear.

thanks in advance