Any thoughts on why after I fill up the gas tank on my '65 Cutlass fuel spills from the vent tube until the fuel level is down a couple gallons? Looking underneath it's coming out of the vent tube at the end of the tube, ruling out a leaky hose at the tank itself. That means it's surging up the vent, over the metal tube "loop", and out the end.
Before I narrowed down that it was coming from the vent tube, I thought it could be the gas cap, as the rubber gasket wasn't in the best of shape. So I ordered a new one from OPGI, and while it was on backorder, it should be here this Thursday. But I don't think the cap has anything to do with it now. I'll try to remember after the next fill-up to undo the cap right after I pull in the garage (which is when I notice the gas overflowing the vent) and see if there is a pressure release when I open the cap. If so, that would mean that pressure is building (when it's not supposed to), and for some reason the the pressure gets to be enough that it "burps" through the vent. That would indicate some sort of partial restriction in the vent line somewhere.
Mike... I'm typing out this "theory" in the event that it jogs your memory to recall what your issue ended up being, and what you did to fix it.