[Dave80GTSi]

The only differences between the early and later model year exhaust manifolds are their exhaust flange dimensions.

See my pictures in Post no. 2 here: http://986forum.com/forums/performance-technical-chat/72706-whats-difference-between-early-late-cat-delete-pipes.html

While I have never had a need to try this, it seems like it would be possible for an early model year car to fit the later model headers (like these Fabspeeds) if the secondary pipes are also swapped to the later models as well.

Thanks - DM