My thought was to not have a basemap at all, just locally published map services. My application has no need for layers other than the services we are publishing, though I see that the projection is set by the basemap. So maybe I need to save one of our layers as a tiled layer and use it as a basemap for the sake of the projection? Would section lines be something one could use for that?
The projection is set by extent the map was initialized with or, if no extent was used in the map constructor, by the first layer added to the map, whether it is a a tiled service or a dynamic one.So, if to the code above you add:
var service = new esri.layers.ArcGISDynamicMapServiceLayer('http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StateCityHighway_USA/MapServer');
map.addLayer(service);
the map spatial reference will be set to the layer's one: 4326