Hi, I want to add an electrical speedo to my Chev Belair. Its very hard to stick to a 50km/h speed limit when the diff and wheels have been changed and the speedo is in mph anyway! I have a VN Speed Sensor which fits in the old powerglide. Can I fit a VN or later speedo without using the ECU? I believe from the Speed Sensor The Black/White wire goes to Earth. Pink/Blue goes to 12V & the Purple/White goes to the speedo. I assume the speedo will need an earth and 12V as well??? Can I recalibrate a VN speedo myself or do I need something later? VT maybe?