[428 78T/A]

Hope someone will chime in with some advice. Im runnin a 428 in a 78 TA with no charcoal canister, return line, or vapor line. Car runs good but has a hell of a vacuum when I take the gas cap off. If I let the car run when Im getting gas itll stall out before I fill the tank.

THen I heard someone on here say that a gas tank can and will crush like a pop can if the vacuum gets too severe.

So as a little experiment, I took off the plug at the gas tank and just ran a straight peice of rubber hose angled up at the gas tank. Sure enough, no more vacuum noise when I take the cap off, which I expected.

Well today after running the car a while I stopped at the post office and when I came back outside the car wasnt running, it stalled. It wouldnt restart for nothin. I walked home came back about an hour later and started right up.

It doesnt stall when the vapor line is capped. It only stalls out when theres no vapor in the tank but Im afraid Ill crush the tank if I cap it. What gives? Do you think the post office had sumptin to do with all of this