I. Relatively Inexpensive & Easy Modifications (Good starting points):
* Intake and Exhaust: This is the most cost-effective way to see noticeable gains.
* Intake Manifold: A performance intake manifold (Edelbrock Performer RPM or similar) will improve airflow into the engine. Consider an aftermarket air cleaner for better breathing as well.
* Exhaust System: Replace the restrictive factory exhaust manifolds and muffler with headers (long tube headers offer the best flow but might require modifications) and a performance muffler (flowmaster, dynomax, etc.). A dual exhaust system further improves flow. Make sure to check local noise ordinances!
* Ignition System: Upgrading to a performance ignition system (e.g., HEI distributor upgrade) will deliver a more powerful and consistent spark, improving combustion efficiency. A good quality set of spark plug wires is also important.
* Carburetion (if applicable): If you have a carburetor, consider a rebuild or replacement with a performance carburetor (Holley, Edelbrock) sized appropriately for your modifications. Proper carburetor tuning is crucial.
II. Moderate Cost & Effort Modifications (Significant gains):
* Cam Swap: This is a major step. A performance camshaft tailored to your intended use (street, strip, etc.) will significantly alter the engine's powerband. This often requires additional modifications like valve springs and pushrods to match the cam's profile. *This is a more involved modification and often requires professional installation.*
* Cylinder Head Work: Porting and polishing the cylinder heads will smooth airflow, improving breathing and horsepower. This can be done by a machine shop and is more expensive.
* Headers: (as mentioned above, but worth emphasizing): Long tube headers provide the greatest performance increase over stock manifolds but may require modification for fitment on your Nova.
III. High Cost & Advanced Modifications (Substantial gains, but complex):
* Engine Rebuild/Stroker Kit: A complete engine rebuild allows for upgrading internal components like pistons, connecting rods, and crankshaft. A stroker kit increases the engine's displacement, substantially increasing horsepower. This is very expensive and requires significant mechanical expertise or a professional engine builder.
* Forced Induction (Supercharger/Turbocharger): This is the most expensive option but yields the greatest power gains. It requires extensive modifications to the engine and supporting systems (fuel system, cooling system, etc.) and can be extremely complex.
Important Considerations:
* Tuning: After any significant modifications, proper engine tuning is essential to ensure optimal performance and avoid damaging the engine. This might involve professional dyno tuning.
* Supporting Modifications: Increasing horsepower may require upgrades to other systems, such as the fuel system (fuel pump, fuel lines) to deliver sufficient fuel, cooling system (radiator, water pump) to handle the increased heat, and transmission to handle the increased torque.
* Professional Help: For any modification beyond simple bolt-ons, it's highly recommended to seek the advice and assistance of a qualified mechanic or engine builder.
Start with the relatively inexpensive intake and exhaust upgrades. This will give you a good feel for the improvements you can achieve before investing heavily in more complex modifications. Remember that incremental upgrades yield the best results and provide a better understanding of your engine's response to modifications.
