Hey thebatman, those numbers on the port maps are the distance in mm from the top of the barrel to the top of the ports, I know, my scrawls are not too good, in fact, my wife calls them chicken scratches, but hey, that's life. You shouldn't need to adjust the height of your cylinder, it should be correct from the factory, I bought a cheapy off ebay so that was what I had to work with. With your cdi derestricted you will get 50 but she will be SCREAMING.