55mater,
Not an expert, but I have set many rear axle gear sets in my 30 plus years as a mechanic. The pattern is a little hard to see, but it looks a little shallow to me. You got a good start, but need more detailed photos. Did you use a micrometer when you set it up? Did you check the backlash with a feeler gauge? Do you have the Chevrolet truck shop manual? All the specifications are in that manual.
Tim
