I bought a Summit Racing harmonic dampner for my 1969 351W, part number SUM-B64269. It is 6.610 inches in diameter compared to 6.2 inches for stock. The really great thing about when you buy this balancer is that neither the Summit web site nor the sales person taking your order will tell you that there is no timing pointer available for this balancer and that you will have to fabricate your own. Is anyone aware of a timing pointer for a 69 351W that will fit a 6.6 inch dampner? I guess anyone who has a fluidampr is in the same spot (6.625 inches)