I'm upgrading the fuel system on my 300TD, which I'm going to write about on my diary thread soon, but in the meantime I have a question. A replacement tank was fitted a few years ago, before I bought the car. The metal fuel lines running the length of the car are both 8mm OD, but the tank has one 8mm & one 10mm, the upper connection being the 10mm. (Someone had used a 10mm rubber hose on the 10mm connection from the tank and just clamped it down onto the 8mm undercar pipe.) Logic would suggest that the larger bore would be for the send pipe, but the return hose was connected to it. (My guess is that the original tank had both 8mm send/returns, but this is a tank from a multivalve or turbo with higher fuel flow needed and thus the larger send capacity.) Does anyone know whether my thoughts about the larger bore being the send are correct and the tank had been plumbed up wrong, and/or have a diagram of the connections to the fuel tank? Thanks.