It doesn't matter as far as I know....The main thing is you match the sending unit with the gauge so the gauge will read accurately.......If you are unsure which sending unit to get do what I did....I recently bought a set of used gauges and had no idea what sending unit to use with the fuel gauge as there was no instructions....So I just got some resistors in the values you listed from radio shack, a 9 volt battery, and a few small pieces of wire and hooked them up to the gauge to see what I had....Turns out I had a 10 ohm 70 ohm....bought the proper sending unit already in the fuel cell and now I am good to go