Brad, I believe the actual instrument "gauge" is the same for the full gauge 63 dash, and the 64 - 66 dash. I know the dashboards are completely different, but once you break down the instrument clusters, the individual instruments/gauges are interchangeable. At least I'm 98% positive that that is true for the tach.
P.S. I found a company that restored these clusters. Everything working and looking brand new including mounting my tach(200 extra for tach) and putting a clock in that space to the left - ballpark $900 - 1k. That's why I have Dolphin Gauges.
