I always turn drum and rotors when I do brake jobs. yes most of the time you can get away with out turning them but I dont like to take that chance. I even turn new ones also as they get out of shape a lot of time in shipping. I would not install a new drum on my front hub and not turn it. It cant be true with out turning it with the bearing races in the hub. And never just do one side. You buy them as a set install them as a set. A bad brake job can take a life.