[JoeC]

The Yenko alu blocks came out long after the 1969 Yenko cars. Chevy sold the alu blocks up until the early 1970s then discontinued them. Then Chevy allowed Yenko to have some made using the Chevy tooling. The Yenko alu blocks were used in SCCA road racing Corvettes, sprint cars, drag cars, etc. I don't know of any Yenko street cars that used the Yenko alu block.