tank venting question

A post 71 filler tube slides in from outsde the quarter and will not work propely. The pre 71 had a vent tube built into the filler tube and will fit a 71. I have a 71 what I did was knocked a hole into the top of my filler neck big enough to run a 1/8 pipe tap in. I then inatalled a threaded hose nupple and attached a pre 71 vent line. I did this to keep my 71 painted cap. If I was goung to repaint a cap I would have just used a pre 71 fill tube with the vent line, I have them if needed for pictures of what they look like or for sale.Steve