Last year I did a little test that included putting in a original factory sending unit to replace a repro which I think is a spectra. Before doing this I ohm tested both units per the factory book and both read within specs well the factory unit read correct when put in the tank and the repro did not. I put the repro back in because I run 3/8 and the factory one I had was 5/16 so until I know of a accurate repro or get a original unit in 3/8 I will live with it I have not tried the bending the arm method yet.