If the SR71 was at Mach 3.2, the tertiary doors (4 outboard, 3 Inboard) would be closed. The convergent/divergent ejector flaps (the nozzle) doors appear to be fully open in which state the SR71 could travel at Mach 3.2. The last stage of the J58 turbojet is in front of the four afterburner spray rings which is front of the afterburner liner.