Some 216's came from the factory with a hat-shaped metal deflector that fit on top of the valve stem between the rocker arm and the valve. Those engines didn't have a stem seal. The valves intended to use O rings will have two grooves at the top. The bottom one gets the O ring and the top gets the split lock keeper. You can also use an umbrella-style seal that rides on the valve stem and deflects oil away from the top of the valve guide.
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!