I disagree as to the value of having the rocker pivot on needle bearings.
The rocker does not actually rotate in use, it only oscillates perhaps 20-25 degrees, and only about 1/3 of the rollers at the bottom of the trunnion carry the load. This is expensive overkill for most engines, they don't last as long as bushings, and a failure showers broken needles into the oil drain and in between the spring coils - meaning, don't buy any knock-offs for $115. on eBay). Somehow, eBay hasn't heard that "all products made outside the US must be identified as to country of origin", so none of them say "Made in China", and if you ask they won't answer you. "Gold Series" does not mean Crane Gold Series. Some are not self-aligning and need guide plates, they generally say so.
For a motor with stud rockers, full roller also means much more money than just roller tip since the entire fulcrum is now completely different (not a ball and cup) and has a miniature individual shaft or trunnion.
