Has anyone converted their 4 lug to 5 lug? I know you can buy the whole rear trailer arm section with the 5 lug brakes to convert the back but,wondering if the 5 lug hub will fit the 4-lug front A-arms. I believe the A-arms are the same but,would like to be sure before I go wasting my money. Also,I currently have drums in the back,will the existing master cylinder and proportioning valve work with the rear disc upgrade?