Boxster piston ring end gaps?

[Homeoboxter]

I still don`t know if the 2.5L and 2.7L piston rings are interchangable. Based on the dimensions (bore size and thickness) they should be identical. However, the sellers say the 2.7L rings won`t fit my 2.5L engine based on the catalog. Am I still missing something here? I already posted some info about the ring end gap measurements in my show&tell gallery and asked the same question there: http://986forum.com/forums/show-tell-gallery/73917-blue-boxster-resurrection-project.html
Perhaps more people read this thread and there`s somebody out there who has seen both of these engines apart and know the answer? Thanks!