trying to locate new gas cap

[dakman]

hey there.. my gas cap is toast and can't seem to find the proper vented one. It's a 72 but the tank has been changed at some point as there is a vent line routed out from the cab to the charcoal canister thats capped off at the tank. The new tank only has one line comming out of the top (supply) and no provision for the second vent line otherwise I'd reconnect it. The vented caps I've found have the locking feature to far down the neck where the one on there now is right at the top. They look identical other than that. Just figured someone might have run into the same problem and might have a part number for the right one