I bought a Spiyda kit and in spite of very good and constant technical help from Spiyda, I was not able to get it to work. Spiyda sent me a replacement kit (actually two, one was lost in the mail) and I was not able to get that one to work either. Serge’s video is very clear and there is another, more detailed, pair of videos from a guy who uses a Spiyda kit to convert his Jaguar tach. He was also successful. In the end, I sent my tach to West Valley Instruments (
https://www.westvalleyinstruments.com/) who knowingly chuckled when I told him what I had tried. Either he’d seen it before or possibly, he was tooting his own horn, so to speak. It wasn’t nearly as inexpensive as the Spiyda kit but it does work and according to the guy at West Valley, will work with any ignition.
Obviously, the Spiyda kit can work but I did everything the instructions, the guy at Spiyda, Serge’s video, and the Jaguar guy’s video said to do and I couldn’t get mine to work. The good news is that the Spiyda kit is inexpensive so it’s worth a try but I felt compelled to relay my experiences.