What duty cycle Matt? Is the car daily driven?
Based on the Joejoey information I threw around some figures;
260kw = 81% of 320kw
therefore, 81% of 550cc injectors = 440cc injectors running at 90% duty cycle
however, if running 480cc injectors instead (440cc/480cc = 0.916) should give you 90% duty cycle * 0.916 = 82.5% duty cycle, which is pretty efficient as I read it is desirable to be under 85%.
This is assuming all things are relative lol
Waits for flaming...