I replaced my OEMs with Bilstien 4600 front and rear on my 2010 Ram 3500 4x4 SRW megacab. My 5er is a 2014 Keystone Alpine 3500 RE which is almost 39' long and about 14K lbs. No more bouncing and feels better on rough pavement on the road. Best price I found autoanything.com with 20% discount beat amazon and pepboys. Side note - don't know if it is true or not but told Bilstien 5100 are for lifted trucks?? Nicer solid ride when not towing than OEMs.