I got a set of old school umbrellas. They are way different. They are called Oil Savers and Valve Silencers. Looks like a little plate and they go on top of the valve stem under the rockers.

I was surpriced that I found them as a stock item for early 216 engines in my Chevy Parts manual.

Question: How tight have oil seals to seal?
Don`t the valve stemms need some lubrication to prevent wear?

Frank

To old to die young.