What do the cam lobes look like? You can install new lifters on an old cam- - - -just do the same break-in procedure you would use with a new cam, 15-20 minutes at high idle (1500-2K RPM on initial startup) to let the lifters wear-in to the cam. If the cam lobes are showing noticeable wear or rust pits, swap the cam also.

Those are solid lifters- - - -no doubt about it.
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!