Yup on the good possibility that it could be a late 69 Camaro axle.
http://www.camaros.org/drivetrain.shtml#axle
"Most late 69 (after 08A) axles (10 or 12 bolt) were stamped using the 1970-style code, e.g. CBT instead of just BT."
Only the late 396 blocks got the 3 letter engine code.