Can't remember, but I believe that the original from an '82 would have one. I am using a manifold from an '83 and it has one. I know that if it has the comp controlled BBD then it will have the O2 sensor.
There was a discussion a while back about when the computer controlled BBD's came out and it sems the concensus was 1983. This manifold (and later) will have the O2 sensor hole already in. The Howell kit does come with an O2 sensor bung to weld into your exhaust pipe if you don't have an O2 ready manifold.