THESE WILL WORK GREAT AS IS FOR ALL CT90'S K2 THRU 1977 BUT CAN ALSO BE USED ON 1978 AND 1979 CT90'S AS WELL AS ALL CT110'S IF YOU JUST REROUTE THE CRANKCASE BREATHER HOSE, JUST LIKE THE PRE 1978'S WERE (BACK_AND_DOWN) THESE DO NOT HAVE THE OIL DRAIN/CRANKCASE BREATHER VENT HOOKUP, JUST LIKE THE PRE 1978 (K2_to_77) MODELS WERE... *CT90 K2_THRU_1977 AIRBOX_NEW MONZA_RED LATER_CT90/110'S READ_DISCRIPTION (CT9/AIR/BX/R110) AIRBOXK2_77Regular price: $79.99Sale price: $69.95 CLICK ON PIC CLICK ON PIC CLICK ON PIC