A lockup kit on a 700r4 is an essential part of any transmission rebuild. It helps to optimize the transmission's performance and ensure that it operates at its peak efficiency. The kit contains several components, such as a torque converter bypass valve, pressure regulator, shift solenoid and other parts required for installation. Installing the lockup kit will allow you to engage the torque converter clutch when driving at highway speeds, which helps reduce slippage and improves fuel economy. When properly installed, this can result in up to 10% better mileage compared to not using a lockup kit. Furthermore, it also reduces heat buildup in the transmission by allowing cooler fluid circulation during normal operation. With improved fuel economy and increased reliability through reduced heat buildup makes installing a lockup kit on your 700r4 highly recommended if you're looking for improved overall performance from your vehicle’s transmission system!