ok, i have a 09 kx250f, and i ordered a pivot works fork rebuild kit, it comes with o rings, bushings, and the seals/wipers. for the shcok i just ordered the MSR shock seal and i guess the seals have bushings on the inside. but as i looked i seen on the shcok piston theres a ring, but it looks like a bushing. the parts list calls it a pistion ring. i didnt order one of these. do i have to replace it? i have 72.2 hours on my bike. any help is greatly appriciated.