Ok since you sound like you know what you are talking about, NO PUN intended, What do you think about performance mods on motors. Here is what I have been told and think. Porting on the intake side doesnt always mean larger and smoother is best, infact most intakes are large enough and alot of them are too large. Some roughness in the runners actually make the gas and air mix more turbulant, is that better? Make sure the carb and intake runner match perfect. The exhaust is better mirrow smooth as well as the inside head dome. Make sure as well the exhaust port matches the header inlet perfect for the transition. I have been using full ceramic bearing in my motors for about a year, without a failure. These are full ceramic, inner, outer and balls, with no seals. I get about 300-500 rpm more with these bearings. Any other ideas???? Thanks