vtec engine wire harness

just want to know if i can use a sohc vtec in my accord. its a 94 lx without the vtec.I have the ecu from a vtec and an vtec engine from an ex accord, do i still have to change the wire hareness, or will the ecu and engine be enough. P.S- the plugs for the vtec ecu and the non vtec ecu are the same.