Hydraulic lifters will have a small spring clip at the top, and a movable plunger inside a hollow body. Unless you can manage to find a set of "new old stock" lifters from the 1950's or 60's, RUN do not walk away from a hdrraulic cam. The current supply of lifters are made somewhere across the pond in slave labor sweratshops, and they fail at an astounding rate. It would be hard to give me a hydraulic cam for a stovebolt engine!
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!