Look at the tips of your rocker arms where they contact the valve stems. You'll probably find that they have divots worn in them that prevent you from getting an accurate lash setting. You could also find someone to degree the cam and figure out what the lash setting is supposed to be instead of guessing about it. Once you're sure the lash setting is correct, any rattle you hear will be something other than mechanical noises in the valve train.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!