Super Large GTP38 Turbo Charger for Ford Super Duty 7.3 PowerStroke Diesel O-Rings 4" Air Intake Upgraded Larger Replacement GTP38 Turbo Turbocharger + O-Rings + 4" Turbo Intake Pipe with Hose For 99-03 Ford Super Duty 7.3L PowerStroke Diesel F-Series, Larger GTP38 Turbo With 4" Turbo Inlet Size. Stock or Many Other Aftermarket Intake Systems Do NOT Fit Larger Turbo. This Kit is a Complete Turbo Upgrade that Comes with Larger Intake Pipe. 4" Pipe Connects Between Turbo Inlet and Upper Intake Pipe. Dramatically Increases Air Flow and Increase Performance. See Comparison Pictures Below Between this Kit and Stock Rubber Pipe. Factory Stock Turbo Inlet is 3", Upgraded Turbo Inlet is 4". This Kit is for 4" Larger Turbo (We Offer Different Kit to Fit Stock Turbo, Please Check Our Other Listings). This Kit Replaces Restrictive Factory Rubber Intake Turbo at the Same Stock Location. Many Aftermarket Intake Systems Offer Different Size of Pipes, This Kits Fits 4" Tube (or Larger System with Proper Reducer Hose) at the Same Stock Location.