K 3500 Truck 4WD V8-5.7L VIN R (1998)
Fuel Tank Filler Neck: Description and Operation
To help prevent refueling with leaded fuel, the fuel filler neck has a built-in restrictor and deflector. The opening in the restrictor will accept only the
smaller unleaded gasoline fuel nozzle which must be fully inserted to bypass the deflector. Attempted refueling with a leaded gas nozzle, or failure to
fully insert the unleaded gas nozzle, will result in gasoline splashing back out of the filler neck.