It seems to me that I remember reading that all the fuel tanks besides the C and F are interchangeable. And the C and F are only interchangeable with each other. I believe that the 02 to 04 C models had an in tank fuel pump, where as the 05 and newer went to the external pump setup. So what makes the 05 C tank NOT interchangeable with the other models? My understanding is that the R, N, T, and maybe others have a larger fuel capacity which is the main reason I was maybe considering swapping it for a different model. If they are different, is it something I could change to make fit or work? What exactly are all the issues with trying this tank swap?

I have an 05 1800C spec 2.

Any insight will be appreciated!!