Possible vent solution? Need opinions...
If the motor backfired, you could blow up the tank.
You tank wouldend up under vacuumandit would be harder to to pump the fuel out of it.
You couldn't fuel you vehicle with it running.
If it was this simple, do you think the auto makers would use the complex methods they do?
Just use a charcoal caniter like the 70's cars did
Stock from the factory my old Datsun vented the tank directly to the air cleaner when the motor was running, but diverted the vent to the crankcase when the motor was off. It had a T'd vacuum switch that diverted the vent automatically.
So I guess you could do what you say, just tap it into the air filter instead of the manifold.
Teflon lined hose, and good fitting install practices, will minimize that problem.

