This article by Bob Mannel was sent to me - Interesting Small Block V8 Balancing http://www.fordsmallblock.com/PDF/SmallBlockV8Balancing.pdf Never realized the 260 harmonic balancer had a 26 oz imbalance. I also came across a web site about repairing the rubber in a harmonic balancer. http://www.hbrepair.com/ Anyone have experience with them? Ron Fraser