http://www.fillernecksupply.com/1-3-...sold-per-inch/
http://www.fillernecksupply.com/1-3-...hose-per-inch/
I would contact vendors to make sure that the hose you select will make a sharp enough bend to accommodate your application. The ones I have seen are very strong so it will take some muscle to make a sharp bend.
Also, if you have a local pick and pull junkyard with commercial utility body trucks in stock, you may be able to get a useable hose for a few dollars.
You can get 45 degree and 90 degree and 22 1/2 degree bends (I think) from Gates if you can approximate the bend you need. I used these on the dump box conversion on my 83. The hoses are very long and you just cut off what you don't need. With those 3 angle options, you can turn the sections of two hoses at different angles and join them with a short piece of filler pipe with large hose clamps. (Think plumbing fittings put together to fit a close quarter bend.) This will likely be cheaper (check Gates filler hoses on Amazon or Orielly Auto Parts) and you will get a smoother transition from tank to filler neck. You can find 1 3/8" filler necks and various angle filler hoses at the junkyard, so with some creative fiddling you can also get what you need that way.