SB 1966-68 with AC PN 1110389 Base timing 4 deg. BTDC! mech. adv. starts at 900rpm full @ 4400 rpm = 26 deg. Vac. ADV. starts at 7" and can be 24 deg! at 15" 66-7 95 hp with air gets 40 deg. @ 4400 rpm! but base timing is "O" PN 1110368