Need some help. Working on a 2000 Ford Escort zx2 DOHC sent the head off to machine shop, they returned it to me, missing 1 valve lifter tappet. They claim it was missing when I dropped it off. I know that's BS but I need to get this car done ASAP. Called Ford they advised part is discontinued. Have called a few Salvage places & looked online. Zero Luck. I need suggestions on where to find another valve tappet.