2007 Suzuki C50T installing in tank fuel pump

I have removed the OEM in tank fuel pump assembly on my 2007 Suzuki c50t, I replaced the pump and now having a problems getting the fuel pump assembly to seat properly in the tank , its almost there. I have about a 1/8 to 1/4 inch gap from the mounting plate to the tank. Any information is helpfull. I have taken it out and reinstalled at least 10 times and cant seem get it to seat properly.