As always Twisted, you make some good points to consider. I will see what other responses I get and see what I can find out on my own about the '81 factory VSS working with the Rostra setup. I've had the instrument cluster out a few times (fitting my own gauges in the place of the dummy lights) and I made sure to leave the VSS alone! Where though, do the wires off it go? It'd be more pertinent to know for sure if it will even work with the Rostra system but, I'm still curious. When I gutted the computer out, I don't remember the VSS wires being part of the main pigtail.