First of all, I am going to agree with everyone that it is worth it. But I will say that with the star kit you will get a bigger turbo, which in turn means that you will flow more CFM=More power, and you will have more potential with it. Eventually you will want to build your engine and you will want a big turbo, with my 66 trim t3/t4 I have already pushed 31psi. So therefore I would suggest Star, or build your own kit. Secondly just FYI I ran 11psi with stock everything for over a year.