Yea, it's all cosmetic. Other than badging, grille treatment and tailgate stampings, nothing is different. Some people try to tell you that the GMC is more heavy duty, which is untrue. The only real difference is that the GMCs usually cost more than the Chevy equivalents. When the US military needed CUCV's, they didn't use GMC trucks and Jimmys, they used Chevy trucks and Blazers- and only because they were cheaper (not by much, but when you're ordering a fleet that big, a few hundred dollars adds up).
My best friend's father worked at the GM plant in Marion, IN. He'll tell you that the GMC is the better truck. When you ask him why, he'll say it's because he worked on them.
