What is a seventies look? Jaws? Star Wars? Apocalypse Now? Bonnie & Clyde? Butch cassidy & the Sundance Kid? ....there were a ton of styles back then. Are you after a particular film stock?
Bleach bypass, Flashing, etc was used in the 70s...but overall I haven't a clue as to what a 70s look is and I was there. Maybe you're referring to a faded film stock that we see today of poorly kept film. In the 70s when the films were fresh they looked great, solid colors, etc... nothing was faded, not even close unless it was meant to be, just like today.
"70's look"...your gonna have to be specific. What film? What look? What's you story setting? Atmosphere? Mood? If you know what you want, then you'll probably answer your own question, in this regard. The 70's had as many looks as movies. There are no magic setting on the DVX that would give you a "Godfather" look, "Manhattan" look, or "Five Easy Pieces" look.
i agree with john. first get the art direction, props and dress back to the 70s. then maybe watch new films with 70s look (like "studio 54", "boogie nights" etc) and see what they did. i do not think the colours etc are different, but the framing etc....