1. Intake Manifold: This is the most crucial change. You'll need a new intake manifold designed for a carburetor. Fuel-injected manifolds have passages for fuel injectors and sensors, making them incompatible with a carburetor. You'll need one specifically for a carburetor, ensuring it's compatible with your engine's other components (e.g., heads).
2. Carburetor: Choose a carburetor appropriate for your engine's displacement and intended use. Consider the CFM (cubic feet per minute) rating; too small, and the engine will be starved for fuel; too large, and you'll lose efficiency and responsiveness.
3. Fuel System: The entire fuel injection system (fuel pump, injectors, lines, etc.) must be removed. You'll need to install a new fuel pump suitable for a carburetor (likely a mechanical pump driven off the camshaft), fuel lines compatible with a carburetor's lower pressure requirements, and a fuel filter.
4. Ignition System: While not always strictly necessary, the ignition system might need adjustments. Fuel injection systems often have integrated ignition controls. A carburetor setup often uses a simpler distributor-based ignition system. You may need to adjust the timing or even swap out components.
5. Computer and Sensors: The entire engine control unit (ECU) and associated sensors (MAP sensor, TPS, etc.) are irrelevant with a carburetor. These can all be removed.
6. Air Cleaner: You'll need a suitable air cleaner assembly designed to work with your chosen carburetor.
7. Fuel Lines and Fittings: All fuel injection lines must be removed and replaced with lines compatible with the new carburetor and mechanical fuel pump.
8. Vacuum Lines: Vacuum lines routed to various components (e.g., brake booster, distributor) will likely need rerouting to accommodate the carburetor's vacuum ports.
9. Throttle Linkage: You'll need to install a new throttle linkage to connect the carburetor to the throttle pedal.
10. Tuning: This is crucial. Once everything is installed, the carburetor will need to be carefully tuned using a vacuum gauge and possibly other tools. This involves adjusting the idle mixture screws, the idle speed, and possibly the carburetor jets to ensure optimal performance and drivability.
Important Considerations:
* Emission Compliance: Converting from fuel injection to a carburetor might violate emissions regulations in your area. Check local laws before proceeding.
* Complexity: This isn't a simple swap; it requires mechanical aptitude and expertise. If you lack the experience, seek professional help.
* Cost: The cost of parts, labor (if you're not doing it yourself), and potential tuning adjustments can add up significantly.
In summary, converting a fuel-injected 302 to carburetor operation is a major mechanical overhaul, not a simple swap. It's advisable to weigh the costs and complexity against potential gains before undertaking the project. If you are not highly experienced, it's best to seek professional help.
