Lifter replacement

Assuming it's lifter racket......
Remember the guy who's pushrods were banging in the tunnels?
Or the guy who's rockerarms were sliding sideways back and forth?
Or one that happened to me: a couple of arms were smacking my homemade breather baffles, in my circa 1970 M/T cast aluminum valve covers.........
Or there was this guy one time here, who's pushrod ends did not fit his arms.
Or one time, the rocker arms were hitting the edges of the retainers.