Originally Posted by BenFenner It depends on what version of the pulley you have. If you have the original G-Spec pulley and want 15 degrees of base ignition timing you should set the timing at 17 degrees as shown on the pulley. If you have Version 2 of the pulley (and it will say this engraved by the timing marks) then the pulley timing marks are accurate, and you should treat it as you would any normal pulley.