Just curious as to what the X codes are. Which level of car has which code? I keep hearing about them, but never saw a compiled list that explains it. Hmmm found em. So here they are for anyone else curious about it.

with Z21 (or Z22)
-------------------------------
X11* non-BB, non-Z28,
including SS-350
X22 BBC
X33 Z28
** see note
*** see note

without Z21 (or Z22)
---------------------
X44* non-BB, non-Z28, non-SS350
X55 SS350
X66 BBC
X77 Z28
** see note
*** see note

*COPO Camaros were an exception, as most COPOs were built
out of bodies coded with X11 or X44, with some cars built
from X66-coded bodies.

**Additional 1969 Norwood Fisher codes that could be
combined with the X-codes include:
D80 - signifies the car was equipped with D80 spoilers,
but the code was not always used.
A - CRG is still researching this code.

***Additional 1969 Norwood Fisher codes that were used
instead of the X-codes include:
Z10 - Indy Pace Car replica coupe
Z11 - Indy Pace Car replica convertible
(Pace cars will be discussed in more detail in a planned
pace car section.)


*COPO Camaros were an exception, as most COPOs were built
out of bodies coded with X11 or X44, with some cars built
from X66-coded bodies.

**Additional 1969 Norwood Fisher codes that could be
combined with the X-codes include:
D80 - signifies the car was equipped with D80 spoilers,
but the code was not always used.
A - CRG is still researching this code.

***Additional 1969 Norwood Fisher codes that were used
instead of the X-codes include:
Z10 - Indy Pace Car replica coupe
Z11 - Indy Pace Car replica convertible
(Pace cars will be discussed in more detail in a planned
pace car section.)