Never meant to imply anyone was an idiot. Don't know of his qualifications, but many old-time wrenches aren't comfortable with digging into a modular, and I don't blame them. In any event, I experienced no knock problems after the headswap. Now pinging, that's a different story. You'll need to use premium fuel, since the unmodified '99+ heads increase the compression ratio, but that can be adjusted by modifying/eliminating the swirl dams in the new heads.