I have had that argument with people before, just because the Valve cover does not say HONDA VTEC does not mean its not, but like eg'sforlife said it is such a subtle change over you would never be able to tell. But chances are, if its an EX its either VTEC-e or SOHC VTEC (depending on year). Like my 01 civic ex has air intake exhaust and headers and i still cant feel or hear a change over, but hey thats me