If 5 injectors flow 420cc, and one flows 440 then there is something seriously wrong. Also it wouldnt be possible to tune a car with standard injectors and 63% correction, there just isnt anywhere near enough scope in the main fuel table to get aroung the leaness. Usually you have to have the correction pretty close, or you run out of adjustment in one way or the other in some part of the map. With 550cc inj i ran 80,80,80,80,80.5, 81.5. The othe rproblem is that this difference in correction occurs at all revs/load, so although the problem with fuel rail/inlet manifold design only occurs at high airflows, the correction ;occurs everywhere even at idle.