69 chevy fuel gauge problem with a fuel cell

[painteralg]

Hello all, I have a fuel cell that has a Chevy 0-90 ohms sending unit but my gas gauge reads 1/8 with the tank full or empty the sending unit is currently reading ~48.5 ohms with a half a tank right now. And the float is not leaking. Below is a list of things I’ve checked. Any ideas would be greatly appreciated.
1, With the ignition "on" and the sending unit power lead disconnected the gauge reads past full.
2. With the ignition "on" and the sending unit power lead grounded it reads empty.
3, I removed the sending unit from the fuel cell and with the float at the bottom it reads 2.2 ohms and with it at the top it reads 89.8 ohms.

I’m reading ~8 VDC at the sending unit power lead as well at the fuel gauge terminal at the fuse box. Also does any one know what the G and the S stand for on the sending unit terminals?

Please help!!!! With any ideas. Thank you