Gas tank / sending unit (18 gallon tank?)
 

I have a tank from a 1992 Formula 350 in my car. I replaced the leaking original. Unfortunately the new one seems to be leaking as well. I suspect it from the sending unit lines. They were a little rusty.. more than I really wanted to use, but I had no other option. The sending unit is basically the same as the 88 I took out with the exception of the swing arm for the fuel gauge float. The 92 tank has the taller style baffle, and the swing arm has a notched design to clear the taller baffle.
I am concerned about buying an aftermarket ( less expensive ) replacement since most use the same part number for FI cars. I wasn't able to figure out how to remove the swing arm without destroying it.. though I really was short on time since I had to drive the car the next day.
Any ideas on getting a replacement sending unit that will have the correct swing arm to clear the late style taller baffle, or how to switch the swing arm to a new unit?
The car has been retired from daily driver status, so time is no longer an issue. :)

Also, when I first filled the tank, I got 18.1 gallons into it. Anyone else have an 18 gallon tank??