1. Engine Harness:
* Finding a suitable harness: You'll need a wiring harness from a GM vehicle that originally used a 305 V8. The year isn't critical, but finding one from the same era (early 80s) will simplify things. A junkyard is your best bet. You might even find one already adapted to a different vehicle – this would be ideal.
* Modifications: The donor harness almost certainly won't be a direct fit. You'll need to splice and modify it to match your Cutlass's existing wiring. This involves identifying corresponding circuits (power, ground, ignition, sensors, etc.) and carefully connecting them. You'll need a wiring diagram for both the 305 engine and your Cutlass.
* Alternator: The 305's alternator wiring will need to be integrated into the Cutlass's charging system.
* Starter: Similar to the alternator, the starter needs to be properly wired into the Cutlass's system.
* Sensors: The 305 will have different sensors (e.g., oxygen sensor, temperature sensor) than the V6. You'll need to ensure these are properly wired and connected to the engine computer (if using one).
2. Engine Computer (ECM/PCM):
* Compatibility: The engine computer from the donor vehicle might not be compatible with the Cutlass's existing system. You might need to source a compatible ECM or use a standalone engine management system (EMS). A standalone EMS offers flexibility but is more complex to set up.
* Programming: If using a stock ECM, you may need to have it programmed or reprogrammed to match your specific vehicle setup. Standalone EMS units usually require extensive configuration and tuning.
3. Gauges and Instruments:
* Modifications: The Cutlass's existing gauges may not accurately reflect the 305's performance (e.g., oil pressure, temperature). You might need to replace or adapt some gauges.
4. Fuel System:
* Fuel Pump: The 305 will likely require a different fuel pump and pressure than the V6.
* Fuel Lines: You might need to modify or replace fuel lines to accommodate the new engine.
5. Exhaust System:
* Fabrication: A new exhaust system will almost certainly be required. You'll need to fabricate or purchase a system designed for a 305 V8 in your Cutlass.
6. Mounting:
* Engine Mounts: You'll need engine mounts designed to fit the 305 in your Cutlass's engine bay. These are usually custom-fabricated or require adaptation.
7. Cooling System:
* Radiator: The V6 radiator might not be sufficient for the V8. You may need a larger radiator or an upgraded cooling system.
Resources:
* Wiring diagrams: Obtain detailed wiring diagrams for both the 1982 Oldsmobile Cutlass V6 and the Chevy 305 V8 engine you are using. These are crucial.
* Online forums: Websites and forums dedicated to classic car restoration and engine swaps are invaluable resources. Search for "305 swap Cutlass" or similar.
* Professional help: Consider seeking the help of a qualified mechanic experienced in engine swaps. This is a complex project, and professional help can save you time, frustration, and potential damage to your vehicle.
Disclaimer: This is a general overview. The specific wiring and modifications will depend heavily on the exact donor vehicle for the 305 and the condition of your Cutlass. Incorrect wiring can lead to serious damage to your car or even injury. Proceed with caution and carefully consider your skills and resources before undertaking this project.
