* Carburetion: Single vs. four-barrel carburetors significantly impacted power.
* Cam Shaft: Different camshafts offered varying performance profiles.
* Compression Ratio: Higher compression generally resulted in more horsepower.
* Exhaust System: Restrictive or performance exhaust systems affected power output.
To know the *exact* horsepower of a particular 1978 350 engine, you would need to look at the vehicle's specifications or the engine's identification numbers.