A lot of the CanAm cars ran slightly different length stacks (~15mm?) on the 427 Chevy engines. The SV650 setup looks interesting Syscrush, however I wonder about its effectiveness. From the picture it looks like one stack is shorter because of a height restriction caused by the stock air box. Also there would appear to be about 30mm+ difference in length. To me this would lead to a 'push me / pull me' situation between the 2 cylinders over the rpm range.
I would point out though, that the stock stacks used on the 550/4 are slightly different in length. Both 1 & 4 are longer than 2 & 3, but only by about 5mm. This would appear to have been done so that 1 & 4 could bend slightly inwards. Thus keeping the stock plenum a bit narrower, and also providing clearence around the frame rails on each side.