[SS427]

The 1970 EEC system was manditory on California sold/delivered cars and uses a non-vented gas tank with a fuel vapor seperator mounted forward and above the fuel tank. It is attached to the underbody and has 4 seperate fittings. 3 to the fuel tank and a vapor line running to the charcoal canister mounted on the front drivers side frame rail. There are different canisters depending on which engine came in the car. These also used different carbs and PCV valves and a mirad of rubber lines.

If you are trying to build one from scratch, good luck! Very expensive and hard to find nowadays.
Rick