rossi makes a 2.1,2.5,3.5.4.6

the rayaracing repinch is holding up great so far. did a 8 tank heat cycle, then let her loose. i can't say to much because the engine ran so poorly when i received it. and i'm not sure on the performance of the k4.6HO with the stock gearing and diff fluids. i have an 1/8 ofna buggy that reaches 52mph so it makes the HF look like its not moving... i've decided to use the HF as a basher for parking lot racing. so i need more speed! thinking about taking the CB to 20 tooth. has anyone encountered any problem when running this high of CB with the 51 tooth spur? what kind of speeds can i expect to reach with this setup? if your using the k4.6HO and your reaching speed of 50mph or over please share you setup. thanks peace