fuel sending unit problems

Glad this forum is back in business. I had to put a new fuel sending unit in my 1970 Cuda because the weld around to fuel tube broke and fuel was leaking out. The gauge was working perfect. I bought one at Jegs for $42 and when I still have about 8 gallons left the gauge reads empty. I found a chart on ohms for sending units and saw that when empty it should read 73 ohms and full should be 10 ohms. My new one reads 75.5 ohms empty and 8 ohms full. Is this enough difference to deem the new one junk? If so, where is a good place to buy a good one? thanks
Author: cudanut jim