Reply To: KB 3.5 differences? Home › Forums › Free Flight › The Engine Shop › KB 3.5 differences? › Reply To: KB 3.5 differences? 09/04/2016 at 9:43 pm #77860 SolarCycloneParticipant I noticed a few more differences not mentioned. One has strengtheners on the mounts. Also one is lacking a cooling fin at the top. Can you identify which ones these are from your list? Attachments:You must be logged in to view attached files.