I am swaping a 455 in to a 72 lark there is a thermal vacuum tree on the drivers side front of the manifold with a two wire connector in it. It also has a diode crossing the wires apears to be factory can any one tell me what the wires ar for thankso No:
Yes, that thermal vacuum switch is for the transmission controlled spark advance. It's a pollution device that eliminates vacuum advance in 1st and 2nd gears, then allows it in 3rd gear. Bottom line, you don't need it unless you are doing a concourse restoration. Eliminate it. Run a vacuum hose from the carburetor directly to the vacuum advance and you are done. Take the vacuum tree out and plug it or use the hole for a temperature gauge.
where is the restior at that goes to the coil so I can get full voltage for electronic ingetion thanks for the help
