The fifteen Gs400 1978 (c) (e01 E02 E04 E17 E18 E21 E22 E24 E25 E30 E34 E39) Muffler component parts are all listed in this schematic.
The component with the lowest price in the MUFFLER schematic is the Lock Washer.
Parts such as the Muffler: Bolt, Gasket,exhaust Pipe (nas), Lock Washer, Clamp,exhaust Pipe are included in the Gs400 1978 (c) (e01 E02 E04 E17 E18 E21 E22 E24 E25 E30 E34 E39) Muffler parts fiche.