Which front tank do I actually have?

My front tank on Ernest (1990 F350 rwd Crew Cab ZF5) not sure how much of that matters - is leaking and my patchwork has failed it. Leaks from the top from a rust spot when full and I'm sure the tank is in awful shape and the sender quit reading a signal from that tank as well.

My FSV works fine and the rear tank and sender is new so I don't want to swap to the 38 gallon rear and eliminate stuff since that all is in working order, but I'm not sure which front tank I actually have? There's more than 1 listed when I look this up on various parts vendors.

I'd like to say it's this one https://www.autozone.com/fuel-delivery/fuel-tank/spectra-premium-fuel-tank-f6c/163346_591483_11993

But I'm not sure how to confirm this. I'm seeing 16, 17, and 19 gallon tanks listed. I'm guessing the senders all correspond to what gallon tank you get also and I know I'll need a new sender. I'd take everything out first, but the leak is minor and I do occasionally drive this truck even in winter when the roads are dry out.

All the full size 8 ft bed trucks have the 19 gallon tank, since they have room for it. The shortbeds are the ones that get the smaller tanks.

Ok cool. I guess the next question becomes why are there so many different sending units that say they are all for a mid mount 19 gallon tank?

Any sending unit and tank before around 1985 will have a small hole in the tank and a corresponding small sending unit. Any tank after that will have a large hole, since they modified ALL the tanks when they started putting electric pumps in the tanks

Diesels use a sending unit with no pump but have a return line

460's have a in tank pump and a return line

351w's and 300's have sending units with no return if they were carbed engines. Later when they went to EFI they had electric pumps with returns on the sending units like the efi 302's did.

Then at some time, the efi sending units went with a high pressure pump in the tank. The early EFI engines had low pressure pumps in the tanks and a high pressure pump on the frame rail.

Some of these sending units are getting impossible to find. The diesel type sending units are one of them getting hard to locate.