Gas tank sending unit

[scubasteve16]

Ok PO installed what I believe is a Blazer gas tank in my 64 Chevy Panel. I have a aftermarket fuel gauge that requires a 0-90 ohm fuel sending unit. The sending unit in the tank now is only a 30 ohm sending unit. I have tried to go to local parts stores to find a sending unit but they look at me like I am a idiot. I found a few units that have a 0-90 ohm but they are for a larger tank so thay are to big. The tank I have is what I believe is a 15 gallon or so because it was completely full and I drained 3 five gallon gas cans of fuel out of it. Any info on a fuel sending unit that will work would be great. It has to be a sending unit that has not only the sending unit wiring on it but the fuel line on it.