At 350kw atws there will be no difference between the stage 1 and stage 2 cooler. Good thing about the stage 2 is that you can build on it later....get the intercooler first, air intake later.....and if the power bug is still biting it easy to upgrade to the plenum. Another thing worth considering is that all of the products that I have in the pipeline will fit with my current products...like my soon to be released engine and transmission oil cooler kits. I planed my complete product line up over 12 months ago and they have all been designed around each other. Kev