well i can start the ball rolling. In astras all 1.8 and 2 litre models have 2.5 bar eleccy fuel pumps. aparently some late model 2 litre 8 valves had the pump in the fuel tank. the rest of models the pump was suspended along side the tank. Now, if for instance both the donor car and recipient have the external pumps then logic sugests they are interchangeable.