://www.technoversions.com/TachMatchHome.html
The standard
TachMatch TM-03 is used in most applications. It allows triggering from a coil ignition, HEI, MSD, and ECU tach output signals. It will directly drive most voltage-driven tachometers, as well as vintage tachometers, such as early Sun, S-W and Radatron units which are typically identified by only having two terminals on the back, labeled + and -. With vintage tachometers, the TachMatch is installed in place of the original sender module, which is no longer necessary.
I found this, you may give them a call.