Originally Posted by elmontanero
Uprated guides? meaning? Sorry as I'm not as educated on this sort of things as I could be. Thanks for everyones contribution... can't be happier to have folks on here help.
Better fitting guides. BMW, rather than fitting guides to the valves, uses a one-size-fits-all approach which rarely results in valve to guide clearances that most would consider ideal. Most head shops will start with guides that are too small and then size them to the valve stem for a tighter fit.