16 gallon tank on a long box truck

[Telecasterjoey]

Hey fellas, Here's what puzzling me lately. Lmc shipped me a gas tank last year by accident and said it would cost them to much to ship back and asked if I would keep it for free I said sure lol. Anyways its a smaller tank than the one that was on my truck i think my truck had a 20 gallon this one is 16 and a whole lot shorter. I got it hooked up and it fits and looks great, I'm just wondering where i would get a new filler hose as mines about a foot too short now. Did long box trucks have 16 gallon tanks ever?

Any help would be appreciated!
Thanks!