I'll send you the "period" KN pods my father put on my Z. They even have a worn out groove in them for your side covers. lol
I couldn't get those things off my bike fast enough, they sound like ass IMO. All you hear is: chhh, chh, chh, chh, chhhhh
1975 Z1 900
1994 KX250 Supermoto
2004 KX125
