I have a stock 455 that I would like to "wake up" a little. Any recommendations on preferred manufacturers/grinds that are most suitable for a mild, streetable Olds?

A friend tried a Mondello (Engle) 18/20, and had valve train noise. I'm not sure if he had adjustable rockers, etc. The noise drove him nuts! What would I need to do to aviod noise and ensure reliability?

Thanks in advance.