Built our new wiring harness and have it coming through the firewall laying in the floor of the cab. Figured I better get the fresh air box back in place, and all the switches and gauges mounted up before I selected my harness route and started making 2nd end wire cuts and crimps. I've got more hours than I probably should have put into this fresh air box/heater assembly, originally mine was spot welded together in places and screwed together in others. I drilled pilot holes and used steel rivet