Thanks alien,
i ended pulling the user manual out to have a read and it told me where it was located,
163. water temperature gauge sender unit. this unit is screwed into the cyclinder head water jacket on the RH side of the engine, above the manifolds to the rear of the carburettor. it operates the water temperature gauge on the instrument panel.
On reading that, then looking at the truck i found the hole plugged up with a bolt and the wire cut back next to the distributor. Im unsure of the type of sensor i will have to get as i would think the correct ohms settings would be needed.