The horsepower of a 4.9 Liter V8 Firebird depends on the year of manufacture and specific model. Pontiac didn't use a 4.9L V8 in the Firebird. They used a 301 cubic inch (4.9L) V8 in some other models (like the Grand Prix) but not typically in the Firebird. Firebirds generally used larger displacement V8s.
To get an accurate horsepower figure, you'd need to specify the exact year and model of the Firebird.
