The 48-53 truck 3-speed transmission should be interchangeable.

There was a standard 3-speed and a much rarer heavy-duty 3-speed.

Here is a page with interesting information, including casting codes. And, that information might be correct, even though the article starts off with a half-year mistake in the first line: "Until mid-year 1955, Chevrolet three-speed pickup trucks had their driveshafts enclosed inside of a torque tube pivoted off the back of the transmission."