1939 Ford Deluxe Fuel Sending Unit Question

[jstrez5]

I will be putting in new send unit to my 1939 ford deluxe. I already emptied the fuel from the tank, and removed the old sending unit. It was corroded with rust and the float had gas leaking out when I removed it from the tank. I ordered a new sending unit from eclassics. I have the original gauges on my dash, eclassics claims their sending unit will work with the original gauges in the car. My question is how much gas needs to go back in to the tank and how would I test for a true reading on the gas gauge?

As always any help is greatly appreciated.


Jim