On the new 216 six cylinder engine, introduced in 1937, the vacuum advance was placed on Chevrolet trucks and cars at the right side of the engine below the distributor. A small metal vacuum line across the front of the engine connected to the carburetor base.
This vacuum advance design continued on trucks through the end of this family of six cylinder engines in 1962, however, on cars a change occurred in 1952. For cars, their engines began with new side motor mounts, not at the front of the block. For the vacuum line to get around this side mount the advance assembly changed position. See photo.
Note: When you see a parts book showing the vacuum advance changes in 1952, they are describing a car not a truck.
Using the 1952-1962 car vacuum advance on a truck will require modification on the vacuum line to a different bend. It will definitely not look correct!
1937-1951 Car and 1937-1962 Truck (left) | 1952 -1962 Car – (right)