That's a good point. I'm not sure what they are charging for pulleys, but I can't imagine they are terribly expensive.For a conservative approach, Id start with the 125mm and go from there. Pulleys are relatively cheap, you can always make changes down the road.
Which 52lb injectors are you referring to? From their site or from a different vendor? I was thinking of starting with the 120mm pulley and see what it makes there. But starting with the 125mm may be the better approach.Why not go with the cheap 52lb injectors? I am starting with the 7.5psi on 93 and bap but your power goal is more like starting on the biggest pulley.