5,500 I recently purchased a 2004 3500 dually Duramax (still own my 2500 Duramax which I can't give up). I am trying to figure out what the towing capacity is with a gooseneck. and 4.10:1 axle) 13,000 (14,400)* Silverado 1500 extended cab, std. - Purchase Using Escrow.com, Trailer Insurance & Protection |   document.write('