If any of the lifters are getting oil, they all are. The oil gallery is about 1/2" in diameter, and runs from front to back, past all the lifters. Sometimes the adjustment is pretty critical, as holes in both parts of the lifter must align before oil will flow up the pushrod. With both valves fully closed, adjust the rocker arm to just eliminate any slack, then tighten the nut 3/4 to 1 turn clockwise. Running valve adjustments just don't work!
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!