When I fill up the tank I get spillage and a puddle forming under the car. The tank is relatively new, but the fuel filler neck is old, off of my old '83. I suspect it is compromised and I want to replace it with a new version, which I have. It appears the clamp that clamps the filler neck to the tank is quite rusted, and I can't tell if the rubber seal there is defective or what exactle is causing the leak. I don't see any staining at the tank seams or anything like that, and the leak stops once I stop filling the tank, so I'm pretty sure it has to do with the old filler neck. Anyway, I was hoping someone might know the size of that clamp off-hand so I can source a stainless replacement before I undertake the filler neck swap. Thanks very much.