im adding some outlets in my basement which has cinder block walls. is it preferable to use metal boxes and conduit or is there a reason to use plastic? i notice the existing two outlets in my basement used metal.
Are you finishing the basement? If you are just planning to mount the boxes to the block, you should use metal and use a piece of conduit to protect the cable. This is required. You do not have to run the conduit all the way back to the source.
Use concrete screws. Then if you want to finish it later they will come right down. Conduit too.