Adding a tach with HEI on an L31 Vortec engine - did I mess up?

[msg]

This maybe a question for the engine forum but I have a cluster that I added a tach that I bought from Classic Auto Parts here. (EDIT: Actually this was purchased from Truck and Car Shop OC on Ebay --see post #4 below)

I am also rewiring with the American Auto Wire kit for my 66 C10 and thought I needed to add a filter and wasnt sure how to wire it. I called AAW and they weren't sure how to wire the filter in specifically because there isnt any install notes to know what wire feeds what on the Classic Auto Parts filter. I tried calling Classic but they are closed due to inclement weather.

This was the filter I thought I needed to use, but now I wonder if the tach is even gonna work at all since I have an HEI distributor.

If anyone has added that tach to their cluster with an HEI please let me know what was done to make it work. Thanks.