[mr0077]

Mike, from the smell you mentioned, it sounds like the power valves may be fluttering open/shut at idle...what power valves are you using and what is your manifold vacuum reading? Also 570 RPM sounds a little slow for the idle, and it may be affecting the vacuum. Try an unported vac advance if the cam isn't too wild, and increase the idle RPM (at least for the test) to around 800 for a more stable manifold vacuum.
Were those readings done on a rolling dyno emission machine, or was the cruise RPM just a free, no-load RPM?