I think where the lbf measurements came from were different sources. From the Pratt & Whitney F135 article I can already see that the stats come to 178 kN for the engine, while the High Performance engine, the General Electric/Rolls-Royce F136 is also 178 kN for the entire system. There is a minor change in lbf, but I am not sure these are accurate; I dont know why the secondary engine is labelled High Performance anyway, if I can't find credible sources then I will remove this.   Yes, I know I'm not signed in, but I am The1exile.