[OKGMC4]

In case anybody else does this there is one issue you can have with this setup depending on the brand of gauges. My Speedhut gauge requires a 1-100 volt pulse between 1000 to 250,000 ppm. The Holley software allows changing the pulses, though the factory default is 4000 pulses per mile. The problem lies in the fact that the Holley ecu supplies a ground pulse rather than a positive pulse. My gauge couldn’t find the proper signal so could not calibrate. I had to tap into an auxiliary 12v wire and splice in a resistor to the signal wire in order for my speedo to read any speed. This was shown as optional wiring in my Speedhut instruction sheet but there was no explanation as to why it was optional. But it worked and hopefully someone someday can use this information on their Holley Terminator X build.