YOU CAN USE JUST A PAPER GASKET OR JUST AN ORING BETWEEN THIS AND THE HEAD 313H @ *INTAKE MANIFOLD ORING 27MM_X_2MM 91301-GK4-871 1/20M (R2102) R2102 @ *GASKET INTAKE_TO_HEAD CT70KO_to_1977 ALL_SL/XL70'S (all_CT110's) (CT200?)7/20M (31B) THIS GOES CLOSEST TO THE HEAD ON THE INTAKE SIDE. FITS KO THRU 1977. and all atc70's 22MM CENTER 44MM BOLT PATTERN ALL HOLES ARE CENTERED all SL AND XL70'S TAKE 2 ONE ON BOTH SIDES OF THE INSOLATER 31B @ SPACER CARB INLET OPENING EXTENDER FITS 30MM TO 37MM OD CARB MOUTH'S 1/17P (CARB/ADP/EXT) (S1383)MADE OF GAS RESISTANT RUBBER, THIS WILL EXTEND AND OR ENLARGE THE CARB MOUTH ON CARBS OF APPROX 33MM TO 37MM REAR OPENINGS/MOUTHS CARB/ADP/EXT (S1383) @ 313H LEFT compaired TO 300001.5 RIGHT