Since you can move it off the fast idle by hand says the linkages are good.
You just need to adjust the linkage rod from the coil to the carb leaner.
There’s a post here from Joe Podavano with a good illustration for you.
https://forums.aaca.org/topic/355944...966-chevy-396/
They are correct about an electric choke conversion that is mounted on your carb won’t work on yours. There is a stand alone electric choke that bolts to the intake though.
Like here.
https://quadrajetparts.com/electroni...971-p-399.html
Your linkage rod length can be effected by your carb base gasket. That could be the cause of your choke being wired open.