engine noise

I need to find a mechanic who can figure it out and fix it.

Unfortunately the few mechanics I've spoken with their eye's glaze over when I start talking about measuring for the correct length push rod. I have no clue what I'm doing and when I have to start telling a mechanic why and how to measure push rod length, then I know I'm not talking to the right person. I wish I would have done the same thing when I picked the guy to rebuild and assemble my engine. He's a machine shop owner and he doesn't even own an adjustable push rod. When he assembled my engine he said the rockers were hitting the valve tip perfectly.