Well...I don't want to run 11-13 thousand rpm!...But I have a set of motown 220's with a 54 cc chamber...would this help in the upper rpm range? We usually exit the turns running 3500-3800---- this is a flat top engine at this time ...but I have some 12.5-1 domes lying around I could use....we only run 10-12 times a year....so will get torn down after the season.....