Radiator drain plug location needed

Good. Stop looking. These newer plastic drain cocks are made of plastic, and they use rubber O-rings. There have been way too many instances where opening them just once breaks the plastic in the tank where the O-ring seats up against, then you have a coolant drip about once every five seconds. The fix for that is to replace the radiator. We never use those drain cocks any more. We pull the lower radiator hose loose.

Docs advice is very good on the S series. They put the drain down under the lower hose and below the trans cooler line right in a spot where it drains onto the frame rail. They are very prone to breaking off.