No you don't need the SID files, they're for 2012> premium devices. Your 2011 3790 device uses G2S files however, which are 'GarminAdjacencytoSSID' data. Again follow catymag's advice and look at your GarminDevice.xml for path and previous file naming:
<Path>.System/G2S</Path>
<FileName>D2329150A.G2S</FileName>
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