Exhaust's gone. (Che replacement question)

[Zonda_]

Of course it would go when the tax is due and the rear tyres are bald! Ah well, time to start shopping around for a replacement.  I have one of the ebay che manifold copies, I read in a post on here (that I can't find) that there is an issue fitting the che exhaust to the che manifold? Is this right, seems odd if it is.