On the 300 kit from tyga , you will see that the flanges come out at an angle . Any 250 pipe that has the same diameter connection as the tyga should fit .
These flanges are custom made for the 300 . The outlet of the 150 cylinder is not in the centre of the exhaust studs . You can see that the out let has been offset on these flanges .
They have been made with straight outlets to maximise performance gains , should be roughly 2% This is a rough comparison of custom 300 pipes vs 250 pipes , there was a splutter
that ruined the day .
.http://www.bikepics.com/pictures/2096375/