I've read over at r3v that the cluster will indeed swap over just fine, but that neither the m42 nor the m20 coding plugs will make the cluster scale correctly. As in if you rev to 7K it will actually read 8K, so unless you just like to pretend that your car revs to 8K then there really isn't any point. Elaborate on why you intend to use one, and we can point you in the right direction.