Personally I would have to ask the reason...Why? As TQ and others have said in the past, all it takes is money and time...but then why not get an identical tank and have it reworked, if it is finish or paint, capacity or a customized profile it can all be done without pulling your old tank until your ready. We do want to continue riding while we contemplate what mods are to be done...right?
The issue is not the tank or so much as fitting I would think, but the submersible fuel pump that has it's own mtg and access panel, as well as the electrics feeding it as designed, along with fuel level float assembly matching up to the center harness connector in the frame and tank tunnel area. Need a little more clarification before we can weigh in here.