$8.25 – $9.50
The back-up washer is part of the piston cup kit in the rocker arm. It sits between the leather cup and the o-ring seal.
Western part:
3-3/4″ 1400 350 300
3-1/2″ 1400 350 301
2-3/4″ 1400 350 302
2.75″, 3.5″, 3.75″