Yooper if your useing super knocks with uni-bushings you can just turn the knock where you want it. the advantage to the cock vane down knock reciever is on a straight clamp it ahlines the cock vane with the center of the knock groove and on a helical clamp it ahlines the center of the vane with the knock groove.But you can turn the knock where you want if you have uni-bushings so it does' nt matter which knock reciever you use.Hope this helps.