The S-IB first stage increased the thrust to 1,600,000 pounds-force (7,120 kN), and the second stage replaced the S-IV with the S-IVB-200, powered by a single J-2 engine burning liquid hydrogen fuel with LOX, to produce 200,000 lbf (890 kN) of thrust.
How much did the second stage increase thrust by with the integration of the S-IVB-200?
200,000 lbf