[buster73]

Guess most prefer case savers for Mag cases so you should be fine. When starting a rebuild you might look into some extensive machining to bring your Mag case back up to specs. If you do not care about original components, a later Aluminium case from a 3.0 Carrera will work with the some parts of your engine, but is hard to source. Sounds crazy, but a complete later engine (3.0 or 3.2) might be the most economic choice in the long run.

You will have to dismantle your engine and have the case inspected to know how much it will take to rebuild and then decide what is the best choice for you.

If the engine runs fine and you are happy with the performance, I would first continue to drive and enjoy.