I originally set my hyd roller rockers preload doing the tightnen till I feel slight resistance on pushrod and then 1/2 turn more, then lock it down the with a cold engine method. However, I would like to know your thoughts on having the engine at a low idle with cutout donor valve covers and adjusting the rocker while running and hot? I have stud type roller rockers with a TFS stage 1 roller cam. Reason being I have very low Hg around 12, engine running a bit rough, but I have NO tick tick tick. Some have said might be the lifters are too tight?