Houston, I just finished my first gallon on my nova n21bf limited. It was blue thunder 20% sport blend. I want to start using a 25-30 % with it now. I notice you recommend byrons. Would I have to add any shims to this engine to do so with either one, 25 or 30 ? Also, Ive been using dynamite platinum series plugs, cold. The temp here is about 90-95 and even a little hotter in the summer. Ive noticed alot of people run oddonnel plugs in their nova engines. Should I use a cold, medium, or hot plug with these temps outside ? oh yeah, we also have pretty high humidity here also.