i have the same tanks, and had the same problem, I got rid of the ball in there years ago!!
If I could make a sugestion, On these old models they put the gas vents below the rub rail, well they all leak gas!!
When you fill up they will splash out, when you going down the road and stop gas comes splashing out all over!
This was a poor design!! and I am not alone, I have spoke with others that have had the same problem.
What I did was disconect the oringal and left in place as not to have to fix the hole.
Then added New 90* angle ones up higher on the Gunnel step up, Have never had another problem.
Keep up the good work!!
