I have a 2003 Blobeye WRX.

I'm planning on dropping the fuel tank. Hopefully it isn't too bad, but on one or two corners, the seam has started to slightly separate and there's a bit of corrosion in there where presumably they aren't coated.

It might not come to it, and I'll inspect it properly when it is off, but are newage JDM tanks that are likely to be much cleaner interchangeable or do they have different pipework configurations etc? I plan to buy a new filler neck anyway as mine is grotty.

I am aware that you can obtain aftermarket pattern tanks, they're not cheap though.

 

The "basic Fuel Tank" for UK RHD and LHD Euro (WRX and Above) cars is the same from MY2003 through to MY2007 (Blobeye to Hawk)
Pipework may be a different story
UK models (EK) shown below


Similarly for the JDM equivalents (Revision C to G )