apparently on the factory J-2 intake, the 2 secondary carbs only worked via vacuum which worked great for awhile, but then were hard to tune and would get stuck from carbon, etc. Many people just took the outer 2 carbs off and blocked them off. Also, some came from the factory with 3x2 intakes with block off plates on the outer two. Just filling orders. . . and yes, I do need that blower intake.