There is a dealer here in Richmond VA that a couple of cars have been attributed to. The dealer is Hechler Motors (now Patrick Chevrolet..same owners since the 60's) I have heard that they might have had a yellow and a black car, but haven't located them. The Richmond zone office was around the corner from the dealership, and the owners had a really good relationship with the zone. From accounts of some local guys that were around then, both cars were listed as factory cars with L72 on the window stickers, but they could have been dealer conversions. The dealership was pretty big into hi performance cars and 'vettes. They took delivery of 2 ZL1 Camaros,the yellow ZL1 vette, a few COPO's and many SHP cars so anything is possible. I know that they were also very willing to stock high performance cars, and the service manager and lead mechanic drag raced, so anything is possible. They might have also DX'd at least one Yenko Camaro. I have heard that the dealership performed engine swaps on a few Camaros (396 to 427) as wellso a Chevelle wouldn't have beena big stretch. I also have heard that they converted a couple of LS6's to what would have amounted to a version of the L88 with aluminum heads. One of these cars campaigned locally on the street as "Moby Dick."