* Different Transmission Types: The 1986 Caprice Classic likely had a THM700R4 or THM400 transmission, while the 1997 C1500 likely has a 4L60E or 4L80E transmission. These are entirely different transmissions with different bolt patterns, bell housings, and internal components.
* Engine Compatibility: The transmissions are designed for different engine types and power outputs. The Caprice Classic's transmission won't be compatible with the C1500's engine.
* Control Systems: The 1997 C1500 uses a more sophisticated electronic control system for the transmission, which won't work with the older mechanical system of the Caprice Classic transmission.
It's important to always use the correct transmission for your specific vehicle year, make, and model. Using an incompatible transmission can lead to major problems and potentially damage your vehicle.