[forrest1]

Is this an idling sound test? If you advance the ignition timing a few degrees (4 degrees or so), it will quiet it significantly. The burn is more complete before the valve opens--the new cam is probably opening the valve a shade earlier. Do not run it at or near WOT with the timing advanced though, just drive it slow to the test, then home to reset it to original value.

Radio Shack has a dB meter for around $50 if you want to pre-test. Even changing the idle speed may do it, depending on the harmonics in your exhaust system.

If it's a WOT test on a dyno or something, better stuff in the steel wool!

Forrest