My buddy has a 99 si and when he bought the car the guy had two AEM cam gears that he didnt put on yet. My buddy went to have the gears put on and they said they are for a single over cam. I have the orginal box and the # is 23-602B. I looked it up and that # is for the 99-00 si. How much of a difference is there between the sohc and dohc gears, i want to put this on a 00 ex? I dunno if the gear was put in the wrong box, or maybe there were a bunch of idots at the garage, and they dont know what they are talking about. Any info will help.