Emblem identificaton help

[gmc hoarder]

A couple years ago i bought a front clip to a mid 70's gmc sierra grande. I only needed the clip for a couple parts and never really paid attention to the box of extras, but yesterday when i was looking for extra taillights i came across the box of extras from the front clip purchase and found a pair of camper special badges, the trim that goes from the driver side under the rear window to the passenger side with the camper special logo, and then this 3+3 badge. I'm trying to figure out if it goes to this era gmc, does it go for only a certain year, and where on the truck would the badge even be mounted. I've seen plenty of older gmc's and this badge isn't ringing a bell so help with be greatly appreciated. just in-case the picture didn't upload, the badge is about 4 inches long and about 2 inches tall with gold raised 3 and a + that is raised more than the 3's and then the other gold 3. if i made it too confusing its just 3+3 with the 3 being gold and the + being red and its all raised emblems.