so after 227K miles, the fuel level gauge has been super wonky, requiring us to fill up the car, and reset the odometer and fill up at about 300-325 miles.

I inspected both fuel level senders and under a loop I could see the copper/brass button that rides on the resister on the driver's side was worn and using a multimeter saw gaps in the readings....I forgot the ohm range. I did replace that sender as it was easy. It helped, but when empty on the drivers' side, and nearly empty on the passenger side it reports WAY too much fuel available

On the passenger side where the fuel pump is I didn't see the same level of wear, but did notice a difference in ohm range.

My fuel pump in the g35 doesn't look like my fuel pump in the 350z of the same year. My 350z has these springs and cup. The sedan's pump doesn't have springs and the cup seems to be attached to the bottom of the tank. The fuel lever sender on the 350z seems to be replaceable, the sedan doesn't seem to be. The sedan has an extra sensor that is on an arm (no clue what that is), and the hose coming from the driver's side doesn't attach like my 350z.

My questions are
1 - what is the expected ohm range on the fuel pump side fuel level sender?
2 - what IS the correct part number for the WHOLE fuel pump housing for my g35 (vin JNKCV51E25M206487) sedan ? I can't seem to find the same pump based on the images in google searches....maybe my car is japanese made?
3 - Is the ohm range for the 350z fuel pump's fuel level sender the same as the G35 sedan? I would think they would be.....thinking of scavenging the resistor and copper/brass wiper from a used 350z fuel level sender (they sell just the sender for $35)

1) Main sender is 3~80 ohms F -> E, sub sender is 3~43 ohms. Note that the behavior you describe can be from a bent arm, sunk float, stuck or tangled float arm on either sender, not just an electrical issue. See Pp 18 of this ESM section for more info:
https://www.nicoclub.com/service-manual ... 5%2Fdi.pdf

2) There's no assembly, the parts are all separate. Here's the rundown:
Tank Seal Ring - 17342-CE800
Pump w/ Pickup Screen - 17042-AC700
Rubber Pump Support - 17043-4M405
Pump Bracket - 17012-8H300 (Discontinued)
Level Sender - 25060-AM600
Temperature Sensor - 22630-5S700
Filter - 16400-2Y505
Filter Packing - 17044-4M405
Filter Clip - 17571-2Y50A
Filter Seal Ring - 17049-4M400
Regulator Seal Ring - 16618-2Y501
Regulator - 22670-8H300

thank you so much for the response....exactly what I needed and didn't know they were all separate pieces...that is helpful

Happy to help, you're most welcome.