Pull the rocker arm assembly and dismantle it, keeping all the rockers in the proper order- - - -there are 4 different shapes and they must be reassembled in the right order. Check the undersides of the rocker shafts for wear- - - -for some reason, the shafts wear a lot quicker than the rocker arms when they're starved for oil. A seller on Ebay usually has new rocker shafts for a reasonable price.
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!