Sounds just like my valve train, and as Jake knows, I've tried a zillion ways, swapped parts including guide plates, rockers, to non-SA to SA rockers, to aluminum rockers, swapped lifters, swapped valve springs, remeasured pr's for proper geometry and tried a little longer pr's, tried using lash caps, went to heavy dual springs (then broke a 3/8 rocker stud)..fixed that and went back to beehives...finally said f* it and have put over 10k miles on it and have taken the covers off and see nothing abnormal, no usual wear spots so I've just learned to live with it...... And this was not my first valve train, put several motors in my truck and in past cars and never had a problem...