HI,
On a 1981 ford f150, I have 2 tanks. Is the rear tank gravity fed into the 1st (main) tank? If so, how do I connect the two. There is only one fuel guage on the dash. Secondly, I am having a problem with the filler line on 1st tank. One man here said probably a vent hose. I took filler line apart. There is a main hose 2 1/4 " in diameter. There is also a small vent hose (black plastic) inside the fille rline. This presumably goes to the gas tank and also attaches at the gas cap. There is a small hole it fits into. What should I do ? Replace the vent line or can I remove it altogether? Any suggestions on how to jerry rig it? Can I hook the back tank up and just pump gas into that?

Any suggestions please !!

thanks in advance