I have a 14000 lb triple axle trailer that is difficult to launch boat because I can't back trailer and boat into water without dangerously come too close at submerging the rear of my truck. I need a 3"x5" x 5' piece of galvanize channel to replace the 18" channel that came with trailer. My couple is bolted on the 18" piece of channel. I have tools to replace but don't know what this piece of trailer is called or where to find it. I believe manufacture is out of business. Any suggestions?????