Has anyone tried a Leovince slip-on or full system? I have an 07 WR450F with the Yamaha ais kit, ee hand guards, moose disc guard, boyseen quickshot and am ready to add a pipe. After reading the Dr.D thread, I do not want to have to loosen the header to change the oil. I am used to my low maintenece 2-stroke, no header in the way of the filter Ha ha. I am thinking of the leovince or a fmf system.