Forgive me for not being clear. I am running a titan and it is a twin. Maybee I'm wrong but I thought the GT's were also twins. I'll have to check. I now understand another aspect of my confusion. I also was wrong in saying GT550 I am asking about the pointless ignition from the GT500. Anyway my source was an article by Kris Bernstien called "Flexi Flyer: T-500". It is viewable on the T-500 fanatics's page, http://members.nbci.com/tr500/t5005.htm, under the section titled sparks. y question is are these pei's on all GT500's or a specific year?