Don't install any repair parts until you fix the underlying problem(s) that caused the rockers to break in the first place- - - -probably sticky valve guides. The only way to be certain the problem is solved is by removing the cylinder head and doing a valve regrind. People will suggest all sorts of shade tree fixes, but they won't be there with an open billfold when the valves stick again and do more damage.
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!