HEI Tach adapter for Sun Super Tach?

[Lynn]

I ran a Sun II in my car back in the 70's with a GM hei distributor, and don't remember needing a filter. Surely, I would remember having to come up with a filter. I remember it clearly as the gauge cluster was not installed (had been vandalized) and the tach was my only instrumentation. I had a 3 x 5 note card with the different speeds and RPM so I would know about how fast I was going. It was dead on accurate at 3600 rpm, which with my 4.10 gear was 70 mph. Only put maybe 3000 miles on the car that way.