If there is no obvious wear at the fulcrum of the rocker to shaft area they're good.

EVERY old Mopar big block I've torn down had some play, in the fulcrum, that was taken out when the oil pressure went up. Not an area of HIGH tolerances held when manufactured as far as I'm concerned. Or maybe it didn't matter when they knew the lifters would compensate.

If you have a replacement PERFORMANCE cam it may have a "smaller base circle" of which is known to cause more valvetrain noise. The fix is longer pushrods or adj. valvetrain.