Part number 3940077, the complete over-the-counter cross ram "conversion" kit was discontinued in early- mid 1973, oddly enough near the same time as the 3945131 67- 69 disc brake axle assembly (which included all 67-69 Trans Am disc brake, steering and suspension components, including stabilizer bars and bushings) due to low sales volume. Also out at or near the same time, the Camaro fiberglass hood part # 3963832, which would have tied in to the cross ram for Trans Am/racing use (I would love to have bought any of the above !). For the standard ZL2 hood, I bought one in 1974-75 for $80.00, installed it in the parking lot of my local dealer, drove it home.
Last pricing I remember seeing was in the low $500.00's for the complete kit. I do think at one time is was $480.00 and change - somebody can correct me if I'm off. I've slept a few times since those days-
Regards,
Steve