basically because youre changing the duration which the air comes in and flows out and youre using a different ecu then what the cam was originally made for more hp yes, emitions legal no
You would have to do tuning to try and make it emitions legal, but it depends on what state you live in as well, cali = sol pretty much

but i wouldnt be able to tell you if thats a cam that would work in it, dont know what cams are swapable with the 6cyls'