In addition to my "Trash Can" condensers, I have available an electronic device that allows just about any current 12 volt negative ground tachometer to be run on a 6 volt positive ground vehicle. It is simple to install and connect and will drive just about any tachometer from a $10 "swap meet special" to a $600 Autometer with memory and playback. These have been extensively tested and have proved accurate and reliable. They have sophisticated circuitry to "clean up" the power anomalies present in vintage vehicle electrical systems. In comes with a comprehensive instruction and installation manual.
Here is a link to a short video of the device in action :
https://www.youtube.com/watch?v=TaxpuDkWAqc.
Here are pictures on the device mounted on the firewall of my 1951 Ford Club Coupe and a picture of the Sun-Pro tachometer head I have mounted on the steering column. The third picture is of a high-end "Mooneyes" tachometer in a '49 Plymouth using the same device.
They are available to board members at $125 plus $8 domestic shipping.You can PM me here or email me at
[email protected] if interested.