After researching, I am still not able to find a definitive answer. Currently I have the stock ep3 engine with intake and headers, but I just bought a JRSC race kit and a k20a2 engine. I don't plan on swapping right away, but I do plan on putting the s/c on. When I do swap, I will also be swapping the supercharger onto the a2 as well. What is the best spark plug to use on either or both engines? I know I need colder plugs, but which ones? Sorry if this has already been answered. Thanks