make model and year would usually be more helpful in determining axle identification, but this one sure looks like a Dana..
here's some other posts with pictures, dimensions, and other tells to help identify exactly what it is..
to paraphrase, the Dana case model is cast in one of the corners and the gear ratio is stamped on a tag..
good luck!
http://67-72chevytrucks.com/vboard/s...48&postcount=8
http://67-72chevytrucks.com/vboard/s...75&postcount=6