I am doing some research for a friend who may have blown the head gaskets in his 99 GT with the ej25d. Would it be possible to swap the ej253 from an 05ish Legacy into the 99? I am thinking we would have to use the intake manifold and associated parts from the ej25d. If we did the swap would we have to use the ecu from the newer car or would the ecu from his 99 work with the ej253? Thanks for the help guys.