On mine with the XE284H-10 using normal 10w-30 oil it was annoyingly noisey
at idle when hot. A simple change to Rotella 15w-40 oil made a huge difference.
Is very acceptable now. The XE284H-10 cam does perform very well.
Give the lifters the rocker nut preload adjustment they need. There are may factors that effect this.
Mine likes and needs a good full turn of preload. No problem with rpm. (decent hi perf springs)