For you guys running electric fuel pumps and pressure regulators, here's my issue. Quality domestic pump, Holley regulator, gauge reads just shy of 4 psi at current adjustment on a stock 283 and Holley 650 carb. Third port on regulator plugged. Pump and reg close to tank, '48 chevy truck with stock tank, vented cap, one fuel line connection from tank. After driving several miles and returning to garage, and after shutting engine off, pressure holds steady at same psi for quite a while, then I sometimes hear a hiss, maybe inside carb, fuel pressure gradually declines, and definately have gas smell inside garage. As I move closer to air cleaner the smell of gas is strong. Should I have a pressure holding steady after turning off engine, and if so, why does it possibly bleed off into the carb? And sometimes it acts flooded when trying to restart. Today it was acted flooded after sitting for several days. By the way...manual choke on older model Holley.