I have fished the northern (Manly) side of the Spit Bridge for Kingie's before with a little bit of luck. On the ocean side of the North bank there is a sandstone retaining wall. About 70m from the bridge there is a red mooring buoy (or there was, i think it's still there) just off the shore, cast towards it, burley if possible and you might have some luck. I bagged three Kings at that spot one morning, one going to 75cm. That was last year though but i can't see why it would've changed. Good luck!
Cheers,
Mark