Modify the intake system: Replace the stock air filter with a high-flow air filter and install a cold air intake system.
Modify the exhaust system: Replace the stock exhaust manifolds with headers and a high-flow catalytic converter. Install a cat-back exhaust system with larger diameter pipes.
Re-program the ECM: Re-program the engine control module (ECM) to adjust the fuel injection and spark timing. A custom tune can be created using a tuner or by using an aftermarket performance chip.
Increase compression ratio: Increase the compression ratio by installing higher compression pistons. This will require thicker head gaskets and possibly longer connecting rods.
Install a camshaft: Install a camshaft with a more aggressive profile. This will change the timing and duration of the valve lift, resulting in more horsepower.
Port and polish the heads: Port and polish the cylinder heads to improve airflow. This involves smoothing out the ports and removing any casting imperfections.
Install roller rockers: Install roller rockers to reduce friction in the valve train and improve airflow.
Upgrade the fuel system: Upgrade the fuel system to supply more fuel to the engine. This may include installing a higher-flow fuel pump, injectors, and fuel pressure regulator.
Internals: For even more power, consider upgrading the internal components of your 350 TPI such as the pistons, connecting rods, crankshaft, and camshaft.
Supercharge/Turbocharge: Adding forced induction such as a supercharger or turbocharger can result in significant horsepower gains but will require additional modifications.
Nitrous: Nitrous oxide injection is another way to add horsepower to your 350 TPI, but it should only be used in a controlled environment and with proper safety precautions.
Professional assistance: It's highly recommended to consult with professional engine builders or performance shops to ensure that the modifications are compatible with your engine and your goals, as well as to ensure the proper installation and tuning.
