Any rocker has a fatigue life, and that life is shortened by unnecessary abuse from an unstable valvetrain.
Ask yourself this, "If I make the valve stem height taller, what do I have to do to the rocker pivot"? The logical answer is, "I have to raise it by moving the shaft". But, the valve is on an 18 degree angle, so then you would recognize that the shaft and valve were now closer together. You would then tell yourself, "I also need to move the shaft away from the valve to maintain the proper spacing, or I need a shorter rocker". All these conclusions are from the application of logic.
Now look at what Indy has done. They put a longer valve in the head, and left the cast shaft stands in the same place (shaft too low). Now the nose of the rocker is jacked way up in the air, and the roller is barely on the valve tip. Their fix was to make the rocker longer, when they should have made the heads with relocated rocker stands, to at least get them close to where they are supposed to be, because the current geometry is attrocious. Your best bet is to get a paired rocker system ($$$$) from T&D, and set them up per instructions. You will have to mill off the shaft stands, and use pushrod oiling, or a spray bar, but you should only have to spend the money once.
You can't just find a rocker that bolts to the cast stands, and has good geometry, because no such thing exists. Mainly, because it is mathmatically not feasible. The rocker design is only part of the story.
I hate be a cold shower, but I'm only telling you the truth. Sometimes the BS sounds better.