Rock Krawler Brake Lines

Ok well i bought the brake lines from rock krawler because they had the longest i could find at the time, well the fron ones are fine, but the back, i looked at the stock square piece and its formed to the axle, but the rock krawler brake line is just flat on the bottom.. well i know that something with a flat bottom isnt going to seal to something rough so what do i do? any help?

little dab of RTV sealant.

where should i put the RTV sealant on at and should i let it dry before bleeding the brakes, and should i use the little brass washer that the front brakes use?

there are washers that have a rounded side and a flat side that go in between the axle tube and the brake line, where you can get them i dont know but i know they have them cause i had one.