This is a dicussion from the
SQUAREBIRDS FORUM and is FE specific, but applies to any MEL application that uses a hot air choke (not all MELS use this system- some are hot coolant operated)-
KULTULZ
The choke stove works this way-
Fresh filtered air is usually sourced from the carb horn under the air cleaner where it is then drawn to the exhaust manifold choke heat stove by engine vacuum. Depending on year and style, it is then ingested into a filter, heated and drawn into the carburetor choke housing where it supplies heat to actuate the choke spring.
A dedicated repro kit should be available for you car-

- 03-35.JPG (20.73 KiB) Viewed 36216 times
Your's will (may) not have this exact setup, but will give you an idea of function. Below is a later 1968 428 assembly-
I do not have a detailed shot of an early 390 other than the POLICE.
-COMPLETE DISCUSSION HERE-