Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 999 / 749 > 998R & 999R engines different?

[chillo]

Does anyone know if there is any differences between 02 (998R) model year engines and 03/04 (999R) motors??
I would be quite suprised if they are identical?

why is Chili is running a 999RS motor in a 998RS chassis?(998.5 as he calls it!)
if thats the case what is the benefit with the motor from the 999??
and doesn't these motors have to be homolgated??