55.2-59 55.2-59 Fuel Tank and Fill Question

[JP2120]

I have a 55.2 3100. Installed a sidefill rear mount tank and a filler assembly with door from a 88 chevy truck. My problem is that its really hard to put gas it in. The filler neck has a 5/8 hose with a free flowing filter and the tank has a vent hose that runs above the tank. The slope on the filler hose is around 30°

The filler neck also has that small spring loaded flap that the nozzle pushes out of the way when filling.

I was thinking of removing the neck and cutting the inside of the filler neck to get rid of that little flap and making the fill hole bigger like the old school filler necks.

Has anyone here had this issue or does anyone have any input pertaining to this problem.

Thanks in advance for any input.

I have attached a picture of the tank and the side fill fender location