The lowest price component in this Muffler parts-list fiche is the Lock Washer.
On this parts fiche the Lock Washer is the most specified component.
The Gp100u 1979 (n) (e01 E02 E06 E13 E14 E24 E30) Muffler consists of nine pieces with the Muffler Assy (to 14301-39670) being the most expensive.