upper engine rattle

i have an upper engine rattle. 340 bored to 373. i pulled the right valve cover and it is getting oil to the rocker shaft and rockers. oil pressure is 60 psi at start up. running 20/50 for oil. the only change i have made to the engine is mopar preformance valve covers. nothing is hiting on the new valve covers. i do have the local mopar god coming to look at the engine but asking for help shouldent hurt.
thank you in advance.

james