HELP - Fuel Gauge issues

370z1

Has anybody installed an aftermarket Fuel Level Gauge? I am interested in doing this to ad to my other after market gauges I have installed but am having trouble finding the Resistance values to my 2011 370Z Sender unit(s) in order to purchase the correct gauge, ie: (? Ohms = Empty) & (? Ohms = Full). Also I am a little unsure since we have two tanks one behind each seat but am guessing their configuration is a Primary Tank and Secondary Tank whereas all readings come from the primary tank as the secondary tank feeds the primary tank by a vacuum line so its function is like a reservoir and the existing digital (The DOTS) fuel level gauge takes the average from both sensors from the primary tank only (I believe)?

I searched the web and looked here for any DIY Fuel Level Gauge installation threads that would help but can't seem to find these answers so any help would be greatly appreciated...

2. Which Sending Unit do I connect the after market Fuel Level Gauge to?
3. Where should I tap into the sensor for the gauge wires?
3. What Resistance (Ohm) values do I use when purchasing the NEW Fuel Level Gauge ie: "? Ohms = EMPTY" and "? Ohms = FULL"?

I own a 2011 370Z with Sports Package (Stick) with the Stillen SuperCharger.

Thank you guys in advance if you can help point me in the right direction. If you want to see the gauges I have installed already have a look at my photo album i there should be some pic in there.

Thank you again for your help.....

My factory gauge works fine just want a different style of gauge so IF I can tap off the PCB behind the Instrument Panel I am ok with that but figured that won't work since the analog data has already been converted to digital so I believe I will need to pull off the sender sensor directly just don't know the resistance values nor where the access point is?