Hi, nice model. The first thing I would do is turn on primitive normal display and check the direction of the normals for those polygons. You can also bring up the display options ('d' in viewport) and enable Remove Backfaces under the Optimize tab. That will turn off visibility for polygons facing away from the viewer.
The Reverse SOP can flip the direction of normals if that is the issue.
Or perhaps you have vertex normals on your geometry and they were modified upstream. In that case you could either remove any N attributes on your model or apply fresh ones with the Normal SOP. Either way I'm guessing the issue is your normals.