well if the sohc ecu isnt vtec it isnt kicking in obviously but its ex..so i assume he is running the stock vtec ecu. i believe the dohc ecu for that motor has a much more aggressive fuel curve than that sohc...not to mention diff red line.. only thing i could think of that is making the engine top out so low is its not gettin the fuel it need, no vtec(if not the stock ecu), whatever it is get it fixed asap...would suck to blow a new motor. try sellin the ecu to get some cash for another ecu... or just get it chipped or something for like $50 but im sure there are alot more people here who have a better clue on whats happening than i. hope i could help