I have a '72, the anti-spill valve in the 1/4inch vent line failed. I had to remove it so my tank could properly vent into the charcoal canister. Do I have to replace that anti-spill valve?
I would say no so long as it's vented. "It might be" that if you ever park downhill on a "San Francisco" street with the tank clear full, that it could siphon some fuel out I don't know The vapor separator is sposed to take care of that I believe.