I am replacing the fuel lines of my c4500 and would like to just replace the line fitting/sending unit on top of the tank while I am at it. It is also pretty rusty. The single tank attached between the frame rails behind the rear axle still looks pretty decent, so I plan to just wire brush it and repaint it. Anyone know of a good source for these fittings/sending units? I have not pulled the existing one yet, but I'm hoping there will be a part number hiding somewhere.