Don't forget the COPO Chevelles. Berger Chevy here in Grand Rapids sold a few of them, I believe 9 of them in 1969 with the cast iron block 427. My dad's got nine Chevelles, four El Camino's, five '72 Chevy Pickups, one of which is a very nice original 402 BB swb truck, two 4x4's (one of which is soon to become my project), and last but not least a '70 K5 Blazer. Unfortunately, while most of his cars and trucks are big blocks and or Super Sports in the case of the cars, no COPO's.
