BC59,
It sounds like you do not have the serial number from the driver's pillar plate or on the front RH frame rail above the front spring?
If you have it, once decoded, it would tell you plant location, year of truck, size (half ton, 3/4 ton, etc), month it was officially produced and then the production number.
cmayna, I think BC59 has all that. What he is looking for is the number of 1960 C10 trucks produced at the Oakland plant. Something that it doesn’t seem GM did a good job of in record keeping or providing such data to the public. Some folks have found full year production data for a few years, but that for the most part was only national production totals, not individual plant counts.
Bill Hanlon’s suggestion to reach out to the GM Heritage Archive I think has merit. It may take some emails, phone calls and persistence to get an answer, but that may be the only source capable of providing such numbers.