I have a 65 coronet 500 convertible with a factory 426 wedge 4-speed. The dash on the left side between the parking brake release knob and the wiper switch is a factory looking 3/8" hole. My friend has a 65 Coronet with factory 426 Wedge & 4-speed and his also has the same hole in the dash. What is it for? Factory Manual Choke? Any advice would be much appreciated, Thanks in advance.