Some of the Sun tachs have a switch inside the housing to select 4, 6, or 8 cylinders. If not, you might have to find someone to do a little rewiring. The old style Sun tach with the big sending unit that resembles an oversized voltage regulator with a brown Bakelite cover would need a total rehab with modern parts to work right, since it had its own oddball Mercury battery power, and the batteries can't be found now.
Jerry
Last edited by Hotrod Lincoln; 12/20/2009 6:02 AM.
