Start with the largest engine listed in the table. In a 1975 GMC brochure, the engine table ends with the 454 four-barrel V8. It would be easy to stop there and picture it in whichever GMC you have in mind. Follow the small mark beside that entry, though, and the possibilities narrow: GMC says it was not available for Series K four-wheel-drive models.
Move up one line and the 400 four-barrel tells a different story. Its note limits it to four-wheel-drive models, and then adds another condition: automatic transmission only. Two neighboring V8 entries lead in different directions. The larger number alone tells you very little about which truck could have it.
Even a familiar displacement needs a closer look. This table gives the 350 separate two-barrel and four-barrel entries. The two-barrel carries both the Series K exclusion and a California exclusion. Those notes are not attached to the four-barrel row. That distinction matters, but the unmarked row still does not supply every model and powertrain combination a buyer could order.
GMC leaves a useful reminder beneath the numbers: consult the dealer for engine, powertrain and model applications, along with trailer-towing specifications. The brochure itself points beyond this little table for the rest of the answer.
For anyone researching a surviving truck, that makes the fine print worth following before drawing conclusions from an engine list. Keep the engine description with its notes, and keep the page tied to the truck it actually describes. This is 1975 GMC evidence. Applying it to a Chevrolet, or carrying its restrictions forward to a 1976 truck, requires the appropriate documentation for that year and make.
The table helps narrow the search. Establishing what belongs in one particular truck takes the next piece of evidence.
Source: GMC 1975 brochure, ADV. 75-3 (8-74), unnumbered back cover, lower-right engine table. Original source photograph.
Scope note: This table does not establish the complete ordering combinations, sales market or original equipment of an individual truck. No Chevrolet or later-model-year application is inferred.