As it would be impractical to drill the A-3517 bushing assembly before it is installed, it is necessary for dealers to drill and tap the two A-20281 screw holes into the bushing after the bushing has been pressed in place (see Fig. 805). When drilling the holes use a No. 21 drill and tap with a No. 10-32 tap.
Do not drill into the bushing any deeper than the length of the shank of the A-20281 screws which are to be installed.