wow.. sweet deals in here. 525 much better then some other guy selling an ap right now for 650 haha. these should all fly off the shelves. good luck with `your sales
the intake design itself is the same. you can actually run a larger filter element on the ms6 since there is more room.
the difference between the two is that the mounting brackets for the ms3 dont work for the ms3 - so you would need to fab up your own mounting brackets for the ms6.