Switching to automatic

Simple explanation:

When the throttle starts to open, the arm on the transmission starts to move. That's how it knows when to shift.

There normally is one long "throttle rod" connecting the carb to the trans on a truck/van. Cars use 2 rods with a pivot in the middle due to lack of room.

How does it connect? Same way it comes off. There's adjustability at the trans. If you have it too slack it'll shift too soft and too early. Too tight and it delays the shifts. Trial and error my friend.

The service manual has the complete procedure in it but nobody has any interest in buying one.

BTW how much help did you get out of "......."?

I converted my car this summer, let us know if you need anymore help with it.