This includes: 1 50mm BOV, 1 air fitting, 1 o-ring gasket. Universal weld on flanges are available in Mild Steel, 304 SS, or Aluminum.

Colors other than bare aluminum may add to order lead time.

Select the appropriate spring for what your car pulls on a vacuum gauge at idle. You need to have a boost/vacuum gauge connected to the intake manifold while the engine is idling to measure this.

For Reference:
• 10psi spring is for engines pulling vacuum values of 16-19inHg (inches of mercury) or 400-480mmHg (millimeters of mercury) at idle
• 11psi spring is for engines pulling vacuum values of 20-21inHg (inches of mercury) or 500-540mmHg (millimeters of mercury) at idle
• 8psi spring is for engines pulling vacuum values of 12-15inHg (inches of mercury) or 300-380mmHg (millimeters of mercury) at idle
• 6psi spring is for engines pulling vacuum values of 8-11inHg (inches of mercury) or 200-280mmHg (millimeters of mercury) at idle