k20z1ej1

As the title states, im wondering if this is a possibility. I have a misfire and have exhausted nearly every imaginable test and part replacement and im looking a mechanical possibilities now. The machine shop i normally use said that the cams or springs could be worn out. Is that a thing for honda engines? ive never seen an engine with 50-60k miles, ESPECIALLY a honda need spring or cam replacement. help me. im losing my damn mind.