No X code

[KurtS]

I doubt that it was originally a Z.
3.31 is the standard ratio for a SS350/4 speed car. 3.73 for a Z.
A 3.31 in a Z would just about be undriveable and a special order to boot.

[DEEJAY]

Never thought about it but makes perfect sense to me.
Thanks Kurt.Starting Total restore,will be posting entire process /photos
     DEEJAY

[69 Z11]

I had a 69 Z with a 3.08 rear, it truly was a pain to drive in town.  Out on the highway though......