As far as I know they are interchangable, the older one is paper and the newer is metal. The metal one is not reusable AT ALL. If you use that and, after properly torquing the timing chest, realise the little chain lying on your garage floor should have been in there, you need to get a new gasket. The paper one can probably be reused lots of times but personally I'd change it anyway (except for that chain incident) because it's a PITA to replace it.