Here is a example of what I mean about being careful.
I have both a 996 and a 998 and although both sets of Silencers are interchangeable the balance pipes are different as the two entries into it that sit under the bike are staggered. On one system the left entry is higher than the right and on the other system its the opposite away around.
http://cgi.ebay.co.uk/ws/eBayISAPI.d...MEBI%3AIT&rd=1 Harness, Radiator, oil cooler, airbox, Exhaust manifolds are also different .