I am wanting (and needing) to tune my distributor to Boss 302 specs, however, there are a few things I need to help with finding. I'm looking for a aftermarket harmonic balancer that is the same diameter and thickness as the stock unit, as well as an adjustable vacuum advance diaphragm. Ford balancers say they wont fit early style timing covers, and also require spacers for alignment. And the only adjustable vacuum advance I saw on summit is this Crane unit, http://www.summitracing.com/parts/crn-99607-1/overview/make/ford, but it says it's for 73 and up distributors with electronic ignition without computer. Anyone know if this will work? From what I have been reading, most of the distributor internals have been the same across many many years. I'm also looking for a set of distributor springs, I think mine may be shot, there is a ton of advance that comes in really fast even with the vacuum adv. plugged. I found 1 pair, I was looking for a variety pack.. Anyone know where to find them?