Get a valve fully closed- - - - -doesn't matter which one- - - - -then apply steady, firm pressure with a pry bar or a long, heavy screwdriver to the pushrod end of the rocker arm. After 2-3 minutes of constant pressure the gap between the rocker tip and the valve stem will increase to 1/8" or more with a hydraulic lifter. A solid lifter will not change gap. The only way a 1954 235 engine would have hydraulic lifters would be a car engine with a Powerglide transmission.
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!