TCI makes it easy to adapt these proven transmissions to any compatible engines by including the exact bellhousing, a special adapter flexplate, pilot adapter, dipstick and other accessories in a complete package. These kits bolt right up to your engine like a stock transmission. The 700R4-based transmission uses a Constant Pressure Valve Body to eliminate the need for careful TV cable tuning, the most common cause of 700R4 transmission failure. If you choose the 4L80E-based 4x transmission, these controls are handled electronically by your choice of the TCI EZ-TCU, TCU 2.0 or a factory GM transmission controller. All 4x transmissions are automatic overdrive four speeds with lock-Up, so simply choose the one that fits your power level.