Torque settings will remain the same, the torque settings represent the approriate amount of pressure to preload the stud / bolt with relative to its yield point, it has nothing to do with the rpm of the engine.

Original rods can be used up to 9Krpm without a problem IF they are worked properly, but unless you can do that yourself it will cost as much as just getting a set of arrows anyway, and as all these rods have seen a fair amount of work now i would say that its best not to trust them at that level, so i would recomend the arrows.