A device modifies the hydraulic behavior of an automatic transmission, specifically the Turbo 400. It alters the speed and firmness of gear changes. As an example, installing one can make a transmission shift more quickly and decisively, improving acceleration.
These kits are valued for enhancing performance and durability in high-performance vehicles. Historically, modifying automatic transmissions in this manner was a common practice to address perceived limitations in factory-set shift characteristics, particularly when increased engine power was applied.