I paid 500 for the dyno for 1 day and 2 of their employee to stay and help with break in and the final tuning. you can check out the video on you tube <iframe width="560" height="315" src="http://www.youtube.com/embed/kmRNzcKKVw4" frameborder="0" allowfullscreen></iframe> you can hear the rocker hitting the valve cover in this vid. http://youtu.be/kmRNzcKKVw4