Francis the red cover could just be a replacement if the original stock one was damaged. The JDM 4G63 other than the cyclone intake is exactly the same as the North American version so the only performance difference would come from how "new" the engine is or its condition. JDM's are not "faster" engines unless it is the GVR4 4G63 with a 16G and 510 cc injectors which is not likely. So yeah what Amin said