* Year of manufacture: Engine designs and technology changed over the years, leading to different power outputs even within the 5.7L 350ci designation.
* Engine modifications: Aftermarket modifications like different camshafts, intake manifolds, exhaust systems, and heads dramatically impact horsepower. A stock engine will produce considerably less horsepower than a heavily modified one.
* Condition of the engine: Wear and tear, maintenance, and overall condition affect the engine's power output.
To get a horsepower figure, you need to specify the *exact* engine (year, make, and model of the vehicle it's in) and whether it's stock or modified. Even then, the actual horsepower might need to be measured on a dynamometer for precise results.
You can try searching online for the specifications of the specific vehicle the engine is in. This might provide a factory horsepower rating, but keep in mind that this is for a brand new, unmodified engine.
