Mounting to an outside wall
60 lbs should be hung on studs. If the unit has the mountings go for two. Most newer electronic stud finds if use carefully will be able to detect were your studs are in the wall even threw the cedar shake and outer sheathing. Then I would drill small pilot holes and then use steel screws or lag bolts. Applying some silicone or caulk to the shaft to help keep the rain out. If they supply a mounting plate for it and instructions, follow them to aid you for proper mounting.