We are currently updating our '69 era kitchen and are relocating some if not all of the receptacles. The old cooktop and range that we have now removed, were hardwired and used aluminum wire. We have discarded the old wire and appliances but are now unsure of the proper materials to use for the new outlet. Is there a large difference between pvc and metal boxes, and what is recommended for a range?
I would use metal boxes. Much more sturdy and not very much different in cost in the grand scheme of things.
You mention that aluminum wire was used to the stove. Was that aluminum wire fed all the way back from the main power panel? If so then you'll likely have an electrical box with a receptacle mounted to it that connects to the AL wire. Make sure to purchase a socket assembly specifically designed for deployment with AL wire. (That is of course unless you will be replacing the feed wire back to the panel with copper).