On my 97 the vent tube by the filler cap is the same size as 1/2" copper pipe for home use, thats what I used to Tee out of the vent line. I used a regular automotive after market electric fuel pump and it works fine. When my main tank gets low I open the aux tank valve and turn the pump on and watch the gauge as I go down the road and when its close to full I shut it off at the fuel pump and do the valve later when I stop next time. The fuel pump runs only with key on so I cant walk away and let it run.