When I first bought my 300E, the driver's lock did not work. The dealer had two choices as far as new tumblers. There was a service one that came with its own key that I believe was $170 Canadian. The other was a tumbler that would match the rest of the locks and I believe it was $700. I ended up switching the passenger one with the driver's one. If I recall, I switched the plastic part that has the wires attached for the factory alarm from the driver's to the passengers and voila. Another suggestion is to buy a keyless entry module and do that as an upgrade. You still have a trunk lock that works and a passenger side that works, so you would never be stranded if it malfunctioned.

Hope this helps,
Steve

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1997 E320
1990 Nissan 300ZX Twin Turbo (Stage X+)