Just to make a post to help give other's ideas, here's a pic of the gauge setup I did for my daughter's 72 442 clone. They're Classic Intruments' Hot Rod series, and they fit perfectly in the opening of the dash insert. Since the dash insert size is near identical on other A-bodies as well, it should be easy to install these in any 64-72 A-body and others too.

One issue I was concerned with was the fact that once you replace the factory speedo, you will loose the high beam indicator, turn signal indicators, and in some instances the brake light. I overcame this by installing LEDs with these chrome bezels that match the rest of the dash well.

I wired everything into a plug that allows me to install & remove easily, and go back to the factory gauge setup if I choose.

Opinions are welcome, and appreciated!

 

Looks good to me! Nice job!