The one here doesn't seem to be magnetic itself...a magnet does stick to it though..
No markings inside either...just what looks like the chalky remains of coolant inside and what made me think of the waterpump bypass plugs..
I used to swap the bypass plugs for a fitting to hose into the truck style 4-core rads I'd pull out of Caddy deathmobiles at the boneyard...most guys seemed to prefer to stay away from parts off these!.
~ Pete
