air shocks....to do or not to do

I'll throw my 2 cents in too.
I've got air shocks on my 75 Dart. I did it to improve ride height.
I've got a similar set of coil over shocks on my 74 Duster. They were there when I bought it.
I have installed KYB shocks on a professional basis for several years.
I can say this, if all you want to do is replace the shocks, you absolutely cannot go wrong with the KYB's.They are a superior shock and will serve you well. They cost a little more than Monroe or Gabriell's, but are well worth the extra money.
Now, the given the history of the A bodies and their tendency to rust at the frames, there is no way I would use air shocks or coil overs without thoroughly inspecting the underside of the car. If it is completely safe, I wouldn't hesitate to use either type shock. The air shocks will offer some flexibility in ride height where the coil overs stay put but are more forgiving with ride quality. The one thing I will say about the air shocks, don't take them to more than a inch or two. That's really pushing it too. any thing over that will just cause havoc.
Regardless of what you do, I recommend that you also replace the front's also.