B2200 Fuel tank differences

OK, I know that the tanks are different between fuel injected and carb, the fuel injected tank has baffles around the pickup to prevent starvation.

Are the tanks different between shortbox, longbox and cabplus?

I believe the tanks may be different, and different sending units. Possibly Cab Plus and long bed are same as they do share the same chassis.

Short box tanks are shortest. Long box uses a longer tank. The cab plus tank is a modified version of the long box tank, in order to fit the front portion of it under the cab. So the answer to your question is, they are all different.