Believe it or not but you can have a perfect 1.5 rocker as tested on a bench test and when install will not be a true 1.5. Just the angle of the push rod changes the ratio. I was almost stunned at this when we were checking some rockers on an engine and the ratio wasn't even close. We were checking with a hyd. lifter on a cold engine and the lifter in time had bled down. We pulled the lifter and disassembled an old lifter and shimmed the plunger to the desired preload depth and found that the difference in just that amount of change in the plunger depth was shocking. This was a couple of years ago and I don't remember the numbers but he has them on record. He had 3 new sets of new adjustable Crane rockers and went through just about all of them to get 1 matched set and these were even short on ratio because of the angle but at least they were even. He has all this on record so when he orders his cam he has that amount ground in do that he has the exact grind that he wants. The rest were reboxed and returned.
