Upper radiator hose

i need to replace the upper radiator hose on a 71 demon 318 engine. The old hose is a 1 5/8 ID hose. After two days calling and visiting every local auto parts chain and on multiple web sites I am unable to find such thing. Everyone insists the hose is 1 1/2". It is not. Any ideas for a source for the correct hose?

Thanks.
Alg