Measuring is a good idea. It never occurred to me because I have never found a tight rocker bearing in any tunnel I have worked on. I have always installed locking rocker feed bolts to keep the bearing in place and I have always been surprised at how well they have worked. The advent of the long bearing seems good, although I have never used one. I am always surprised at how long it takes to modify the rocker when using the locking rocker feed bolts on high-lift cams.
David