When did GM first introduce the COPO option ?

[JoeC]

here is an interesting article on a COPO

this looks like about 1964 or 65

As far as I know, The first use of a COPO to build a fleet of race cars was the Yenko COPO on Corvairs

Yenko used Corvair COPO 9513A and 9681E and others in 1966

there was a COPO 9719A 1965 Chevelle with 396 L-78 and other hi po parts that was not a RPO Z-16