* 4: Four-barrel carburetor
* 42: 425 cubic inch displacement engine (though this wasn't always the case; other engine sizes were offered).
Therefore, there's no single answer. To know the stock engine for a specific year's Oldsmobile 442, you'd need to specify the model year. Common engine options included various sizes and configurations of Oldsmobile's V8s, such as:
* 330 cubic inch V8: An early option.
* 400 cubic inch V8: Became a very popular and common engine in 442s.
* 425 cubic inch V8: The engine that gave the 442 its name (though not always standard).
* 455 cubic inch V8: A high-performance option in later years.
In short, you need to specify the year to determine the stock engine for that particular Oldsmobile 442.