First of all what kind of hp gain can I expect from this swap with the mods in sig? Next how difficult is the swap it self? Has anyone done this what are some of the little problems that you ran into? I am getting this motor dirt cheap. Should I rebuild the motor before installing it? It has about 37,000 miles an runs as of the time it was pulled from the car(totaled in the rear end). Is the entire swap worth it or should I just swap the heads an intake? Please guys give me some direction hear I have to let the guy know what parts I want by the end of the week.