You might take that rocker off and look at the ball.. It may have extreem wear for aome reason.. Perhaps a prior valve job has led to more wear in that area.
Rockers with balls can be purchased individually.. Might be a good idea..
The longer pushrods are what I install in used heads. Even with a new camshaft I use them and have never had a problem.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

professional bovine relocation specialist