I'm looking to attach a few panels to the walls and crossbeams on my 2013 Nissan NV2500 High Roof using Rivnuts and Plusnuts (Cross Nuts) but I can't seem to find the wall thickness information. I have the service manual and the bodybuilder's guide but I can't seem to find the information in there and I need it in order to get the right grip range (thickness) for the nuts. Thanks