Have you checked for valve retainer to valve guide clearance? I've read on here that .520 is just about max for uncut LA heads. You have .533 lift on the exhaust side... might want to check clearance. Not saying for sure but might be the noise you're hearing.
Guessing it's according who you talk too...LOL... but with the lift you're running... if it was me I would definitely go adjustable roller rockers. I had a push rod bust straight through two of my stock rocker arms running a .474 lift cam. After that I went adjustable roller rockers.
