my truck has been making tapping noises for awile now..figured it was a valve tap so i checked it out an #4-5 rockers where kind of loose an not lined up to good with the valve!they both had spacers on them too.. I tightened them up an no valve tap but is that wrong rocker arms or shafts or something? both rockers were barely on

 

sounds like the keeper springs were bad or broken and they slipped off. id say grab a set off a 22RE thats a bit newer. they had aluminum lifters. same ratio but a little lighter. frees up a little rotating mass.