408 Valve train noise??

What rocker arms If they are rollers, it may be normal for some noise. Also keep in mind, those nostalgia cams from Comp are ground specifically to take advantage of the Mopar .903 lifter diameter. That means that series of cams has more aggressive lobes then their standard "Chevy" style lobes. So it might be normal for that as well. Since we cannot hear it, we have nothing to go by.