I'm wrong, looking at it more closely - the M97 manifold requires a single bolt between ports which is centrally placed between the ports, but offset from the centre line, and there's no boss on the M96 head in that position.
Rather than modifying the plastic intake my gut feeling is that it would be easier to build up the head with weld then drill and tap it in the correct places.
I'm wrong, looking at it more closely - the M97 manifold requires a single bolt between ports which is centrally placed between the ports, but offset from the centre line, and there's no boss on the M96 head in that position.