Chevy 383 (often a stroked 350):
* Displacement: 383 cubic inches (6.3L). It's important to note that a true factory-produced 383 was not offered by Chevrolet; most "383s" are modified 350 small-block Chevys with a longer stroke crankshaft.
* Power Output: Power varies wildly depending on the build, but generally less than a 454. Think of it as a strong, potentially high-revving engine, but not as brutally powerful in terms of torque.
* Torque Curve: Relatively broader torque curve than the 454, potentially making it more versatile for street driving.
* Weight: Generally lighter than a 454.
* Application: Often found in performance builds where a higher RPM range is desired, or when a more compact big block is needed.
Chevy 454:
* Displacement: 454 cubic inches (7.4L). This is a true factory-produced big-block.
* Power Output: Significantly more horsepower and torque than a 383, especially at lower RPMs. Think massive grunt.
* Torque Curve: A very broad, flat torque curve, meaning lots of low-end power.
* Weight: Heavier than a 383.
* Application: Ideal for towing, hauling, or applications requiring massive low-end torque. Popular in muscle cars and trucks.
Here's a table summarizing the key differences:
| Feature | Chevy 383 (stroked 350) | Chevy 454 |
|----------------|------------------------|----------------------|
| Displacement | 383 cubic inches (6.3L) | 454 cubic inches (7.4L) |
| Power Output | Lower | Significantly Higher |
| Torque | Less, but broader curve | More, flat torque curve |
| Weight | Lighter | Heavier |
| RPM Range | Higher potential | Lower optimal range |
| Typical Use | Performance builds, street driving | Towing, hauling, muscle cars |
In short: The 454 is a significantly larger and more powerful engine, better suited for applications requiring massive torque. The 383 (modified 350) is a smaller, potentially higher-revving engine that can be built for various applications, but lacks the raw pulling power of the 454. The choice depends entirely on the intended application and desired performance characteristics.
