Originally Posted by AndyF
Probably just need a vented gas cap for your make and model.


FWIW after some study I gave up and ordered a vented cap based on your advice, and this note in Ehrenberg's auction: Great upgrade for pre-'73 A-bodies: Two-way check valve solves tank venting problems forever. All vent lines on tank can be capped off!


69 road runner A12 ex-racer
71 Duster w/ a 400

Shiny paint causes stress.