Winchester 1400 12ga. barrel

[SpeedySB]

I need a new barrel for my Winchester 1400 12ga automatic. The barrel on it will only shoot 2 3/4 inch shells. Will a barrel that shoots 3 inch or 3 1/2 mag shells fit or work on my 1400 ?? Does any one know where I can get a full choke or extra full choke GOOD USED $ INEXPENSIVE $ barrel ?????

Thank you,
SpeedySB :)