This saved me some money, thank you very much. I wanted to purchase the kartboy to replace my spt but it won't make a difference in my setup. I have a sparco knob that uses the set screws to mount it rather than threading on. the sparco knob allows me to mount it further down on the shift lever which makes it almost identical to the kartboy. Hope that makes sense. According to your write up, one could cut the spt one down a little bit and re-thread it and get the same result if I am understanding right.