I have a 97 k1500 with the 350. Recently I had the truck in for repair for a random tick. (ticked worse with warmer weather

) He changed the lifters (found 3 that he considered bad) and push rods, and after many tries to adjust the lash, it still ticks on startup if it has set for a few hours.
Before it would tick until warmed up, now it only ticks for a few seconds.
Does anyone have an idea what he may have missed for it to keep ticking like this? It is a little upsetting to pay out almost $800 for parts and labor for it to still have a "tick". thank you, cartman0223