Noted between the last 986 model of 2004 and the 987 at introduction
Variable ratio power steering
Stiffer chassis, wider wheel alignment
Bigger brakes
Head airbags
PSM standard
17” wheels standard (18”, 19” optional)
Improved headlights (not just in looks but in the non-Litronics better lighting)
More cockpit room
Better positioned roll bars
http://sites.google.com/site/mikefocke2/modelyeardifferences