I. Planning & Parts:
* Engine Condition: Assess the condition of your chosen 327 or 350. Does it run? Does it need a rebuild? This dictates the cost and complexity considerably. A running, rebuilt engine makes the swap much simpler.
* Transmission Compatibility: Will you reuse your existing transmission? If so, is it compatible with the new engine (bellhousing bolt pattern)? Consider a rebuild or upgrade while you're at it. A different transmission (e.g., automatic to manual) dramatically increases the complexity.
* Engine Mounts: You'll need engine mounts appropriate for your specific engine and truck frame. These might be original-style mounts, or aftermarket upgrades.
* Exhaust System: Your existing exhaust likely won't fit. You'll need headers or a custom exhaust system.
* Wiring Harness: The engine's wiring harness needs to be compatible with your truck's system. This might involve splicing, rewiring, or using a universal harness. Consider a standalone engine harness for simplicity.
* Cooling System: Check the radiator, hoses, thermostat, and water pump for compatibility.
* Clutch (Manual Transmission): If using a manual transmission, you'll need a new clutch, pressure plate, and throwout bearing (likely).
* Torque Converter (Automatic Transmission): For automatics, ensure you have the correct torque converter for your transmission and engine.
* Other Accessories: Consider alternator, power steering pump, distributor, carburetor/fuel injection, and other accessories. Are they compatible with your engine and truck?
II. Tools & Equipment:
* Engine Hoist: Essential for lifting and positioning the engine.
* Socket Set & Wrenches: A comprehensive set of metric and SAE tools.
* Jacks & Jack Stands: For supporting the truck safely.
* Torque Wrench: Crucial for tightening bolts to the correct specifications.
* Wires & Connectors: For electrical work.
* Shop Manual: A factory service manual for your truck is highly recommended.
* Parts Cleaning Supplies: For cleaning engine parts.
* Welding Equipment (possibly): For fabrication or exhaust work.
III. Steps Involved (Simplified):
1. Preparation: Disconnect the battery, drain fluids, remove the old engine, and clean the engine bay.
2. Installation: Install new engine mounts, position the new engine, and connect the transmission.
3. Hook-up Accessories: Attach the alternator, power steering pump, and other accessories.
4. Wiring: Connect the wiring harness, ensuring proper grounding and connections.
5. Exhaust System Installation: Install the headers or custom exhaust.
6. Cooling System Installation: Connect the radiator hoses, water pump, and thermostat.
7. Fluid Filling: Fill the engine with oil and coolant.
8. Testing: Start the engine and check for leaks, proper operation, and correct temperatures.
IV. Considerations:
* Skill Level: This is an advanced mechanical task. If you lack experience, seeking professional help is strongly advised.
* Time Commitment: Expect this to take several days, even for experienced mechanics.
* Cost: The cost varies greatly depending on the condition of your new engine, the parts you need to buy, and whether you do the work yourself.
In short: While technically doable, swapping a 327 or 350 in a 1978 Chevy pickup is a challenging project that requires significant mechanical knowledge, the right tools, and a substantial time commitment. Thorough planning and preparation are absolutely essential for success. If you're unsure about any aspect, consult a professional mechanic.
