I am about to order parts to install disc brakes on my 2017 tracker 190 trailer.Questions I have are . Is the tongue of the trailer at the hitch 3in need to know so I can order the Demco hyd brake actuator. And will the Kodiak disc brake kit 10in rotor, 5 on 41/2in hub size work, this kit is for a 3500lb trailer. Also are the springs 26in, gonna replace those also with 3500lb springs. TIA.