I am in the process of replacing my gas tank for my 1970 chevelle malibu 2DR HT. I don't know which type of tank it is. I did various searches and there are gas tanks with EEC or ECC, with out EEC or ECC, and with 1-3 vents. I don't know what these things mean. I don't think the one on my chevelle is the original, I don't really know. When I checked my gas tank from the back it has one output sort of in the middle where the gas come out through the gas line, which seems to be comming from the top of the tank, and then there are three other small pipes (in the middle and the other two on each opposite corner) plus all three of them are taped up at the tip not going nowhere. HELP, which gas tank should I get?