Had this happen years ago, I had a lifter ticking I would retighten it and it would start again, it ended up that one of the pressed in rocker studs was pulling out with the higher valve spring pressure and bigger cam lobes, ended up having to put in screw in studs. Not that this is your problem but "This happened too me"! Check and see if the stud length on the rocker nuts protrude all about the same and ones not lifting. Also Welcome!