I recently picked up a Disco V8 for offroading, the person before me had removed the original fuel tank and installed a alloy one with no fuel sender in it, ive installed a universal fuel sender and would like to make it work with the stock fuel gauge, ive found two unused plugs under the Disco, can anyone tell me if either of these are for the fuel gauge and if the stock fuel gauge will work with a universal sender.

On mine it uses the long plug on the bottom right of your picture. The best way to check is to look at the wiring diagram.