* Internal Components: The camshaft (profile and duration), pistons (compression ratio), connecting rods, crankshaft, and valvetrain all significantly impact power. A mild street cam will produce far less power than a race-prepared cam. Higher compression ratios generally yield more power but require higher-octane fuel.
* Carburation/Fuel Injection: The type of carburetor or fuel injection system and its tuning significantly affect horsepower. A properly tuned system will deliver considerably more power than a poorly tuned one.
* Exhaust System: The exhaust headers and their design, as well as the rest of the exhaust system, significantly influence power and torque.
* Ignition System: A properly functioning and tuned ignition system is crucial for optimal combustion and power output.
* Engine Build Quality: The precision of the engine's machining and assembly directly affects its performance.
A well-built 357 Windsor with GT40P heads and a Victor Jr. intake *could* produce anywhere from 350 to 500+ horsepower, depending on the factors listed above. A naturally aspirated engine on the lower end of that range would be more street-oriented, while a higher horsepower figure would suggest a more aggressively built engine for racing or serious performance applications.
