What I like to do on those flanged interfaces is very lightly flat file the mating surfaces of both flanges to remove any burrs, nicks, uneveness, etc., that might prevent a good gasket seal. By flat filing I just lay a fine flat file on the surface and put light finger pressure on the center of the file and move the file back and forth and also rotate around the face of the flange on both the banjo housing and the torque tube. Then when I bolt those two together, I coat the gasket with grease and snug all six bolts down evenly. Then I come back and final torque each bolt so that one of the wire holes in the head of each bolt line up to allow the safety wire to feed around through the holes in a circular pattern, twist the ends together to give about a 3/4" long twist, cut off the excess and push the twisted ends down against the the flange.