We use these pans exclusively in all of our transmissions. These Goerend deep pan kits hold an extra 3.5 quart capacity. This specific amount is by design. it leaves room for extra capacity from large and dual external coolers. The 47/48re fluid system cannot hold more than 20 quarts of fluid before you run the risk of fluid exhausting out the breather when the fluid gets heated and expands. This pan capacity prevents against this. Using the supplied filter lowering block is imperative to keeping the filter covered in fluid at all times. Without a filter spacer, the fluid level drops during shifting and lock up, allowing the fluid level to get bellow the filter, causing a moment of cavitation. When this happens, line pressure drops and over time will cause premature clutch wear. In a high power application, maintaining line pressure during the shifts is critical for performance and clutch life.