72 gas tank?

ive been told that my 72 nova gas tank is difernt to 68-70 because it has EEC on it.
what is EEC?

http://www.carpartsdiscount.com/auto/parts/72/chevrolet/nova/gas_tanks/gas_tank.html?3593=4051

Got mine from there, says its for a 68-72. I have a 72 and it went in with no problems.

EEC = Evaporative Emission Control. It consists of a charcoal canister on the firewall, a canister in the trunk by the rear seat back and a bunch of tubing. If you use an unvented tank you must remember to use a vented gas cap.

I have a '72 tank for the asking if anyone needs one.