My point is that tuning is not necessary to use the M50 manifold. If you want to mess with the timing, power can be gained with any manifold, since they build in a safety margin from the factory (and as such, it's not an especially great idea unless it's a track car). But the manifold alone does not require any kind of special tuning just for its own sake. A better manifold simply lets you flow more air. The MAF and IAT readings will inform the DME of this and it will adjust the fuel in step.