venting fuel tank?
Since you are using the f-body tank you really need to hook up both valves.
If 350SS was to put a bulkhead fitting in the top of the tank and use maybe -6an or -8an braided line, coiled it around twice(to keep any fuel from splashing out) then ran it closer to the outside of the car and somehow secured the line. Would that be adequate enough to vent the tank for a) filling the tank. and b) the car running(i.e. useing fuel) ?
I used this method on a race car, but not street driving, and it was only a 10 gal. fuel cell..






