While your at it you may want to consider adding a transducer mounting plate. I added one just recently while upgrading my system.
http://www.cabelas.com/product/Cabelas-Transducer-Mounting-Plates/701430.uts?productVariantId=1212857&WT.tsrc=PPC&WT.mc_id=BingPLA&WT.z_mc_id1=02684721&rid=20&gclid=CPnIyp7zjdUCFTm9swodEnoLvQ&gclsrc=ds