Taxi cabs were once primarily the domain of the more affluent segment of society, as regular folks took public transportation. That’s why fine big cars like Packards, DeSotos and Checkers were typically used, at least in New York, where the regulations required a long wheelbase car with additional room in the back.
Here’s Packard’s offerings for 1948: a regular wb sedan, and a “New York-type Limousine Cab”. More details below:
The sedan-type Cab presumably was a variant of the basic “Eight” series, and would have come with the small-block 288 CID straight eight.
And the “New York-type” would be a variant of the Super Eight 7-passenger sedan/limo, with the large 327 CID eight.