Wont fill with gas

I have recently put in a new sending unit and ran all new fuel lines on my truck. After getting everything hooked back up I went to put gas into it in the gas came back up out of the filler neck. I tried using I can and also filling up at the gas station and it still did the same thing. So what could cause it to fill up with air and not breathe. The hose on the filler neck is not obstructed or twisted, the vent line is not collapsed clogged or cracked. The vent line is also ran as high as I could run it so it is not hanging down or anything. Could it have something to do with EVAP? Been chasing so many problems with this truck and it is pretty overwhelming need some input from somebody else.