When I was looking for an alternative to my muffler I had thought about using more of the 996 exhaust system. As you can see from the picture below, it's not the best layout for transferring into the 986. I'm not saying it can't be done, but it didn't look like there was enough room for a 996 muffler. The 996 catalytic convertors wouldn't fit either. The right 996 cat has bad angles for fabricating into a 986. On another note, the 996 system doesn't sound very impressive.
