69 firewall identification mark questions

[Dave69x33]

While restoring my 69Z (Norwood car), I found a couple of markings under the paint on the firewall that I have not positively identified.  I have been told that the "2X" identified heavy duty radiator, and the "10" stood for the RPO N10 Duel Exhaust.  Can anyone help confirm this?

I know the "D8" was for the D80 spoilers, and the "X3" identified an X33 RS Z28.

Thanks

[RamAirDave]

Ive found N10 and D80 in that area on several cars.  Dont recall having found an Xcode marking on a firewall before myself, but certainly wouldnt say its not possible.

[JohnZ]

Don't know what the "2X" stood for, but it wasn't a radiator - Fisher Body had no interest whatsoever in radiators, as they were installed several days later by Chevrolet with the front end sheet metal and had no effect on any part of the body.

[KurtS]

Probably the rotation #, 24.

[Dave69x33]

RamAirDave, I can not be sure about the "X3", the X appeared more clear than what appeared to be the bottom half of a 3.  Can you confirm if the "10" stood for N10 duel exhaust? Where the cars you found the 10 on duel exhaust cars?

KurtS, what was the rotation number?

Who knows.....maybe two buddies were communicating with code where to meet for lunch that day!!?!

[RamAirDave]

In this example, it was "N10" written on the firewall:

[KurtS]

Rotation #/ sequence #. Tracking # used internal to the plant, started at 1 every day.

[cib12]

my 69 rs-ss350(pre Xcode-Nor) has X-1 (looking inside the car towards the rear seat area) on the pass side upper steel panel behind the back upper seat