Jeff,
Check the following thread, as it is closely related and everything suggested applies to your engine. Regarding the spark plug air seals ... if shriveled or cracked, they need to be replaced with VW part 111.905.449 from an independent VW or foreign parts supplier ... NOT a VW dealer, as VW supperceded the part with an 'A' suffix, and it does NOT work on an OEM 911 Beru connector! The aftermarket parts are still being made in Mexico and Brazil, and are cheap ... but make sure the ones you get are soft and flexible, because you need to get a minimum of 12 and keep the spares in your glove compartment! They need to be checked at every oil change, and at least every six months.
http://www.pelicanparts.com/cgi-bin/vb/showthread.php?s=&threadid=63663