i had my front crank seal go out, so i tore the front of the engine apart and went ahead and replaced the timing chain and both sprockets, and i see that on the harmonic balancer there is a shiny "wear" spot from the old seal where the h.b. has been worn down,and im wondering if thsi is normal? and do i have to replace the h.b. or will it be fine to re-install? thanks for the help! '79 c10 - 350c.i.