1. Transmission Selection & Acquisition:
* C4 vs C6: The Ford C4 (used in many Ford cars and trucks from the late 1960s-early 1980s) is generally smaller and lighter than the C6 (used in larger vehicles of the same era), making it potentially a better fit for a Thunderbird, but both will require significant modification. Consider the space available in the Thunderbird's chassis. A used transmission will likely need a rebuild, and finding a suitable one in good condition is important.
* Condition: A professionally rebuilt transmission is highly recommended. A transmission in poor condition will add significant cost and complexity to the project.
2. Fabrication & Adapters:
* Transmission Crossmember: A custom crossmember will be needed to properly support the automatic transmission. This likely requires welding and fabrication skills.
* Driveshaft: The existing driveshaft will be too short or otherwise incompatible. A custom driveshaft will need to be made or sourced. Length, yoke size, and balance are critical.
* Torque Converter: The torque converter needs to mate correctly to both the transmission and the engine's flywheel. This often involves using an adapter plate or having one custom fabricated.
* Bellhousing: A bellhousing adapter will almost certainly be required to mate the automatic transmission to your Thunderbird's engine (likely a Y-block V8). This is a crucial component requiring precision.
* Shift Linkage/Controls: The existing manual linkage will be useless. You'll need to source or fabricate a linkage/control system for the automatic transmission, potentially including a column shift lever adaptation.
3. Modifications to the Vehicle:
* Floorpan: Depending on the chosen transmission and its location, modifications to the floorpan may be needed to accommodate the transmission's size and/or the shifter.
* Wiring: The electrical system will need adaptation to control the automatic transmission (e.g., neutral safety switch).
4. Professional Assistance:
* Transmission Shop: A transmission specialist should rebuild the chosen transmission and potentially help with adapter plate choices or fabrication.
* Machine Shop: A machine shop might be needed to fabricate custom parts like the crossmember, driveshaft, or adapter plates.
* Experienced Mechanic: Even with all the parts gathered, professional mechanical skills are absolutely essential to install the transmission properly and ensure everything works correctly.
5. Other Considerations:
* Cost: This project will be expensive, involving parts, labor, and potential unforeseen issues.
* Time: This is not a weekend project; expect significant time investment.
* Resources: Finding the necessary parts (especially adapters) might be challenging and require significant research.
In summary, a "complete solution" for this swap is not a simple off-the-shelf kit. It's a complex project that requires significant mechanical expertise, fabrication skills, and financial resources. Consider consulting with experienced hot-rod shops specializing in classic car restorations; they have the knowledge and resources to handle this type of conversion. They might even have existing plans or solutions for similar projects. Trying to do this on your own without significant prior experience is strongly discouraged.
