Id. Go with checking your tappets each. Valve guide has to be reamed before changing them out if they seal and work proper id check to see there's not an end cap or anything missing from the tappet. Some systems have a small piece that fits on the end. Valves may be cheap but reamers specifically for valves? Cheapest I found was like 50 bux
if at first you dont succeed get a bigger hammer....