[Nothinghead]

Anything can be done to a truck with enough time and money.

Both of those things can be done. Depends on your skill or budget.

There are companies that do the AC thing. Look into vintage air for one.

I am not sure about the transmission swap, but I imagine that you just get a manual tranny that works with your engine and cut a hole in your floor. May have to change your steering column too.