If there is one 'trick tip' that has come from racing over the last few years it would have to be the practice of cutting a vertical groove from the bottom to approx half way up on the left side [ looking from front to rear ] of each lifter bore so that a fine jet of pressure
oil from the lifter gallery is directed onto each cam lobe /lifter . In fact I think this method works better than the lifters with the small hole on the face. Comp Cams has a special tool & diagram of the process in the catalog.
Jac Mac