Thanks all! My key, being a well worn original does actually have a letter + 4 digit code on it. Am I assuming correctly that it is the lock code?

Zed head option 2 = replace ignition cylinder plug assembly.

AZMarty yes that's the code , usually starting with an ''x'' .

Thanks all! My key, being a well worn original does actually have a letter + 4 digit code on it. Am I assuming correctly that it is the lock code?

AZMarty yes that's the code , usually starting with an ''x'' .

Depends on the year - My 240Z code starts with 'M', as I recall. Later cars have other letters.

+1 Arne .

As well, M , N , VH , X , Y with 4 digits to follow.

Also if codes were ever found, they are 90% of the time on the passenger door lock . Either on the lock housing or the ''pawl'' that operates the linkage.

Also if codes were ever found, they are 90% of the time on the passenger door lock . Either on the lock housing or the ''pawl'' that operates the linkage.

Anyone else find it an interesting point that the codes on a LH drive car are found on the RH door lock. Seems to me, it would make more sense being on the side that is more likely to need replacing first. Just thinking out loud.

Anyone else find it an interesting point that the codes on a LH drive car are found on the RH door lock. Seems to me, it would make more sense being on the side that is more likely to need replacing first. Just thinking out loud.

I'm sure Alan T would point out that makes perfect sense, given where the cars were built (along with the emergency brake handle). Actually, I thought I remember seeing the codes on both of the door locks. Maybe I am not recalling that correctly though. I'll have to check some parts that are off the car.

-Mike