'01 cobra fuel vapors

i'm sorting out an '01 cobra that's had some modifications ('03 fuel tank for one). I replaced the fuel pump gasket, fuel line, restored fuel evap system ($200 in missing parts), and pressure tested evap system. the car now idles very nicely but i still have fuel vapors coming from somewhere. No fuel leaks anywhere obvious. Vapors seem to be on the fuel filler side, not the evap cannister side. Vapors are there regardless of fuel level in tank. Is there a vent line i can check without pulling the tank? thanks -