Fuel Leak

I'm trying to locate a minor fuel leak at the tank in my 68 Dart. I've replaced the filler neck seal a while back. Is there a seal at the sending unit? Other than that and the fuel line itself, are there any other point that tend to leak? I only noticed the leak after I fill up the tank and drive home.
I just put a new tank, sending unit and filler seal in my BC. Within 6 weeks the filler tube seal had a catastrophic failure and now I have to drop the tank and do it again.
Seldom seen a leak at the sending unit seal, it does have a gasket though.