i just mentioned the k series because of the insane amount of power they can make n/a with only a few bolt on mods. they are really pricy tho, but man one of them in a rabbit with exhaust and intake work, and a nice set of cams and u could easily have a 12 second car. i saw a while ago a guy who was running a stock long block on e85 with a big turbo and making over 700whp. totally nuts for an untouched engine... im sure he had cams tho.