I have about .035 valve lash on most of my rockers no preload . Stock rockers the with a flat tapped hydraulic purple shaft cam . No idea which one,Engine already built when I purchased the car. The valves had a ticking noise oil pressure is 45 psi at idle. Checked rockers and notice they were loose. Could it have wrong lifters. I pulled a few bottom looks fine. Check pushrods they are correct length. Anyone every had the problem.