I've had that "rattle" since day one - thought it was a bearing as well, but others who have heard it dont' agree - the SC basically makes the noise when there's some parasitic load on the motor, like at idle when the AC is on, or when coming to a stop at a light and the vacuum swings (tach is slightly below idle). It doesn't make the noise at WOT or even when there's a little gas applied. My friend John Schellenberg surmised it's the screws making light contact when there isn't any compression. Let me know what you find out - also, has anyone contacted Magnuson for parts?

-- John