Here's a general outline. Specific steps and torque specifications will vary depending on the year and configuration of your specific 305. Always consult a repair manual specific to your engine for accurate information.
1. Preparation and Safety:
* Disconnect the battery: This prevents accidental short circuits.
* Gather your tools: You'll need a socket set (metric and standard), wrenches, ratchet, torque wrench, pry bar, engine hoist, jack stands, drain pan, coolant catch basin, and possibly a breaker bar for stubborn bolts.
* Safety glasses and gloves: Protect yourself from injury.
* Consult a repair manual: This is absolutely crucial for torque specifications and proper procedure.
2. Initial Steps:
* Drain the coolant: Allow the engine to cool completely before draining the radiator and engine block.
* Disconnect all accessories: This includes the distributor, alternator, power steering pump, intake manifold, carburetor (or throttle body), fuel lines, and vacuum lines. Label everything carefully to ensure correct reassembly.
* Remove valve covers: This gives you access to the rocker arms and pushrods.
* Remove rocker arms and pushrods: Support the pushrods so they don't fall into the engine.
* Remove the intake manifold: This will vary greatly depending on the specific intake manifold on your engine. Bolts may be difficult to remove if they are corroded. Use penetrating oil if necessary.
3. Head Removal:
* Disconnect the head bolts: These are usually located around the perimeter of the cylinder head. Loosen them in a star pattern (opposite bolts, then alternating) to prevent warping the head. This is crucial. Do *not* remove them completely yet.
* Lift the head slightly: Use a pry bar carefully to break the head free. Be gentle to avoid damaging the head gasket or engine block.
* Remove the head bolts completely: Once the head is slightly lifted, you can remove the remaining bolts.
* Carefully lift the head: Use an engine hoist to lift the head away from the engine block. The head is heavy and awkward. Have an assistant to help if possible.
4. Post-Head Removal:
* Inspect the head gasket: Note its condition. Replacement is usually recommended when removing the head.
* Inspect the head and block surfaces: Look for any damage or warpage.
* Clean the surfaces: Thoroughly clean the head and block surfaces where the head gasket sits before installing the new one.
5. Reassembly:
Reassembly is the reverse of the removal process, but with a new head gasket. Pay close attention to torque specifications for the head bolts – this is extremely important to prevent leaks and warpage. Use a torque wrench and follow the sequence specified in your repair manual.
Disclaimer: This is a simplified overview. Incorrect procedures can cause serious engine damage. Consult a reliable repair manual specific to your 305 Chevy engine for detailed instructions and torque specifications. If you are not comfortable performing this task, hire a qualified mechanic.
