Date matters, auto vs man trans matters, speedo adapter probably matters. But the usage sometimes changes for unknown (to me) reasons.
Here's what I have for 69 (with a caveat for limited data):
CF (May & later) - V8 auto, Z28, BB auto & man
CT (pre May) - V8 auto, Z28, BB man
CV (pre May) - L6 & low-po auto
CW - L48/M20, BB auto & man
CX - L65 & L14 man
CY - L65 man
CH is a full-size code. And I've not seen a CX code on a Z, so I think that cable was changed.