I am researching this also. From the Roush site it appears the jump to 590hp is mainly a pulley and tune. I think you can just get that from them or have your Roush dealer do the install. Who is your Roush dealer??
I am actually trying to turn my 2012 into a 590 hp Roush. I am being told unless I buy the completed truck through a ROUSH dealer I would only have a tuner car even if Roush installs it all. Anyone know the facts on this? My goal is to have a Roush serialized truck with all the parts and the 3/36 Ford warrenty which is void if I just add the supercharger. You would think a dealer would do this for me as my truck only has 600 miles.