On Friday 26 January 2007 04:18, Les wrote: [...] OT >Do you know how to "shape" the springs on the centrifugal advance, or >how to control the curve on the vacuum advance? Yup, been there, done that. Most effective on an old Nash Ambassador big 6. 115mph@19mpg, 70mph@22mpg, whupass on any flathead ford in town. Hard on rings though when you push that engine above 7000 revs. 4 3/8" stroke=4500+fps piston speed=broken rings. Guaranteed. /OT -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Yahoo.com and AOL/TW attorneys please note, additions to the above message by Gene Heskett are: Copyright 2007 by Maurice Eugene Heskett, all rights reserved.