An axle code can look like a shortcut: find three characters, look up a ratio, and move on. Chevrolet’s February 1983 pickup ordering charts show why that can fail. In the NA6 high-altitude sections, GQ1 appears under different ratio columns, even within the same engine and model group. The useful question is not simply “What does GQ1 mean?” It is “Which complete row does this GQ1 belong to?” [1]
Start with the heading, not the code
These examples come from the first 1983 C/K Pickup section of GM’s archived Chevrolet truck compilation. The selected Power Teams leaves are dated February 1983 and headed “ALL STATES EXCEPT CALIFORNIA.” Their NA6 heading identifies high-altitude emission equipment. Those boundaries matter: these are not interchangeable with the adjacent NA5 tables, California ordering information, or later leaves collected in the same PDF. [1–3]
The charts instruct the reader to order the engine, transmission and rear axle, then consult the GVWR Selector and Tire Chart. A power-team row is therefore part of an ordering process, not a self-contained approval for an entire truck. [1–2]
Same engine, different transmission row
On printed page 10, find the NA6 K10703-K10903 group. Its LE9 5.0-liter V8 entry covers two rows, and GQ1 means a different ratio in each. The first row has MM7 in the four-speed transmission column and GQ1 under 3.42. The row below lists MM4 and MX0, with GQ1 under 3.08 instead. GT4 stays under 3.73 in both rows, and both show 6100 in the gross vehicle weight rating (GVWR) column. [1]
Combining those lines would erase the distinction the chart preserves. The shared engine label belongs to both rows; the transmission entries and axle-column positions must stay with their respective lines. GQ1, taken by itself, cannot recover that information.
The rating column changes the reading, too
The C20903 NA6 group on printed page 13 supplies another example. Its LE3 4.1-liter six-cylinder heading includes “N/A C6P.” The rows marked 6400 and 7200 in the printed GVW column each show MM4 and MX0, GQ1 under 3.73, and GT5 under 4.10. The separate 8200 row still shows MM4 and MX0, but puts GQ1 under 4.10. The engine’s C6P restriction spans all three rows. [2]
That is a documented difference between chart rows, not an invitation to mix their entries or infer why Chevrolet specified them. Nor should the literal “ALL” appearing in the C10703-C10903 NA6 gasoline rows be expanded into an unrestricted list of ratings. [1–2]
What a blank cannot tell you
An empty cell, a printed dash and an explicit N/A restriction are different evidence. Preserve each as printed rather than turning every empty space into a universal prohibition. Footnotes also belong to particular marked entries: page 13’s marked axle cells and its separate diesel notes cannot be applied indiscriminately to neighboring gasoline rows. [2]
The practical takeaway is simple: save the heading, engine label, transmission line, axle column, rating and applicable notes together. These examples explain how to read two dated charts. They do not establish every orderable combination, prove what an individual truck received, or provide present-day emissions-compliance advice. The referenced GVWR and tire checks remain necessary, and no conclusion here relies on the compilation’s appended February 1984 diesel material.
Primary sources
1. General Motors, 1983 Chevrolet Truck compilation, C/K Pickup—Page 10, February 1983, PDF page 13. NA6 gasoline blocks C10703-C10903 and K10703-K10903; full page headings and instructions. View source page
2. Same compilation, C/K Pickup—Page 13, February 1983, PDF page 16. NA6 C20903 LE3 block; full column headings, engine restrictions and page-footnote context. View source page
3. Same compilation, PDF page 4, internal “1983 C/K PICKUP” section heading, dated September 1982. This establishes the section’s model-year context, not the revision date of the selected February 1983 leaves. View source page