My 69 Z was built in Van Nuys and has the designation J020 in the lower right where the Norwood cars have the X33 that denotes Z28.... Ive been unable to find any references for decoding this designation; everything seem to indicate these codes are unknown..... any clues please THANKS

Unfortunately, these codes, often referred to as LA Work order #'s, haven't been completely decoded yet. I don't believe they will tell you much anyway.

Could you post the rest of the Trim Tag data and the VIN #?

You can look for the chassis broadcast sheet on top of the gas tank if it's a VN car. You'll need to lower the tank carefully and if you see a piece of paper up there, don't try to pull it out or you could ruin it. You'll want to reomve the tank so you can carefully remove the sheet. There are codes on that sheet that will show if it's a Z28, SS350, SS396, etc. Let us know if you find it. Kurt S. can help you decode it.

couldnt find a build sheet anywhere not on top of tank not in headliner or inside seats or under carpet
but here is the rest of the info
vin 12437 9 L 517024
Cowl ST 69 12437 VN 225511 BDY
TR 711 71 B PNT
IC J020
I already know what the cowl tag means, its just the "J020" that was puzzling.. but it does seem to be some sort of production assigned # that doesnt really have anything to do with the car options i.e. Z28

These numbers were only used at the LA plant and are believed to be production period date coding. They don't tell you much other than an approximate date of assembly. However you can get that info from your VIN as well.

Just a note.....IC is actually 1C (3rd week of January 1969)....