Is it a solid nose bar, or does it have a sprocket in the nose? If it's solid nose, all you would need to switch it to the more common 3/8" chain would be to replace with a 3/8 drive sprocket on the clutch. If it has a sprocket in the nose of the bar, you'd need to replace both the drive sprocket and the bar. It would probably cut better with a 3/8" chain anyway.
If you are stuck on using a .404 pitch, any good chainsaw or logging equipment shop should be able to make you up a loop. Just tell them how many drive links you want on the loop. If you can't find a shop, talk to someone who runs logging equipment - a lot of that equipment runs .404 chains, and many of the operators are set up to make their own loops from bulk chain.
