I know that some of the sohc guys has done Upgraded their udp. I know forward motion make em, but when i called, wither this guy didint know what the hell he was talking about or that everyone else was blowing smoke up my ass about sohc udp. Personally i believe strength in numbers over one tech. Anyways my qestion is, im looking for a drive pulley that noone no longer needs and is looking to get rid of. If you got one gimme me a email.