Here's why:
* Bellhousing and Transmission Mount: Flathead Ford engines use a different bellhousing and transmission mount than modern transmissions. You'll need to find a bellhousing and transmission mount specifically made for a flathead Ford engine.
* Driveshaft: The driveshaft length and spline count will be different between a flathead Ford and a modern five-speed. You will need a custom driveshaft.
* Clutch: The clutch system will also need to be compatible with the new transmission.
* Shifter: You will need a new shifter and linkage to connect to the five-speed transmission.
* Engine Modifications: The flathead Ford engine may require modifications to the flywheel and starter to work with a five-speed transmission.
The process of installing a five-speed transmission into a flathead Ford car is a major undertaking:
1. Finding a Suitable Transmission: You'll need to research compatible five-speed transmissions and find one that will fit with the bellhousing and other requirements.
2. Adapting the Transmission: You'll likely need to purchase or fabricate adapters for the bellhousing, transmission mount, driveshaft, clutch, and shifter.
3. Installation: The installation process will require a skilled mechanic with experience working on flathead Ford cars.
Consider the cost and complexity: This project is not for the faint of heart, and it could potentially cost you more than it's worth. If you're looking for better fuel economy or highway cruising, you might want to consider other options like:
* Overdrive Unit: A simpler solution might be adding an overdrive unit to the existing three-speed transmission.
* Modern Engine Swap: If you're looking for a more dramatic performance upgrade, you could consider swapping in a modern V8 engine with a five-speed transmission.
Before you embark on this project, it's essential to research thoroughly, consult with experienced mechanics, and consider the potential costs involved.
