I think what you are planning sounds cool. I did a similar thing with my 70 Cuda, and previously with my 69 GTO. They looked totally stock unless you measure the sway bar diameter, or measure the rotor diameter behind the 15inch rallye wheels. While neither of them are a track day car, they handle and perform much like a modern car, and I think that is the point.
That is a great looking car, and I can see why you don't want to mess with the styling too much.
