You need a pair of
#6 for each, mine was 91 so these are were a thinner concave updated part to me. you reuse the
#16 collars... my rubber bushings were partially liquified after 24 years. The
#9 is not reused, KW's come with a thin rubber isolator that double-stick tapes into the hat, the upper purple plastic bushing locks into it.
I set mine to 1 click softer bump and rebound then the KW manual recommended setting front/rear, ride is firm but compliant, unlike the horrible comptech silver coilovers and koni combo the car came with.