Replacement fuel tank questio

[Auston]

Hey guys. Ran into my first issue on the 71. I ordered a new spectra tank from rock auto. Everything fit great but my original tank had a fitting in the upper passenger corner whereas the new tank doesn’t. From what I found on here, that fitting is for the vapor line?? If thats correct, I’m assuming it’s no longer needed being as the new tank did not have it. Do I need to plug that off, leave it as is, or what? Thanks for the help.

[RustyPile]

My '71 has the same vent lines. Originally, that line carried the vapors to the vapor (charcoal) canister. Vacuum controlled valves on the canister vented those vapors back to the engine.. The tank you have is for a different venting system.. First, you'll need a way for it to vent or when the fuel pump pulls fuel from the tank, the vacuum created will make the pump unable to pump fuel and the engine will quit running (literally run out of fuel), leaving you stranded somewhere..

Others may not agree, or will offer other options, but I'm of the opinion that you have the wrong tank for your application.. This is the main reason I DO NOT patronize Rock Auto.. Return it and get the correct tank for your application.

[Auston]

Great. I can see how this project is going to go already. Had a 50/50 shot out getting it right and ordered the wrong one. Just my luck. Lol

However, I understand what you’re saying about the tank creating a vacuum and not being able to pump fuel. But, if the fuel cap is vented, wouldn’t that allow air to enter the tank when fuel is pumped out?