i dont even think that the 7m mani will go on a 5mge. 5mge has its dizzy still sticking up on the intake side whilst the 7m has it on the ex side making more room on the intake for the manifold. 7mge manifold would be a HUGE diff over a 5me, maybe not so much over a 5mge or 6mge. runners may be a bit straighter.
also, just thinking, the 5mge being only 2v per cyl, does it have ovalised intake ports? 7mge does, so may not fit based on that alone.