It should be a case of shimming the pinion with the correct thickness of spacers/shims until it has minimal play, but not so tight that it is hard to turn the steering wheel, which should self center when driving down the road or it is dangerous.
There is a cheap Chinese offering of a replacement Ferrari 308 rack that many have used with success. It requires a small modification where the clamps bolt one side to widen the clamping surface.
Julian
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