The box was like the one in this profile (
http://www.streetsourcemag.com/viewownerprofile.aspx?profileid=33261). The early Hombre. It had a Chevy front end and tailgate.
I know years ago one of the GM dealers near where I lived used to get some GM's with Chevy grills (no bowtie on it). Normally, I could see something along that lines as being possible but I find it surprising that something as large as a box would get put on a vehicle, especially a low end base model.