The fuel sending unit on mine was Made by transfer Flow Inc.  out of Chino Ca.  and looks like a 90 OHM,  or a WHO 06.  Mine had a 7  97 date below the WHO 06 .  It also had a standard 5 hole mounting pattern.  I suspect that if you could find a generic 90 OHM adjustable sending unit you could make it fit just fine.  Test before you buy.  The fuel level will need to be below the sending unit.  I believe I got my unit from Beaver Parts sales and it was pricey, but I did not want to remove the old unit until I had a new unit in hand.  You will also need a new gasket that did not come with my sending unit!  If you have time, I would drain enough fuel, take the old unit out, and match it up with a compatible unit at a auto parts store.  
Hopefully this will be hepful!