While recently doing some research on the L-89, I noticed that my reference showed only 18 Chevelles built with this option in 1970? This was the only car I could find with the L-89 option in that year? Is this correct? If so, would anyone have information as to what aluminum head was used (842's??) to get the correct 11:1 compression ratio? My references show the 842's to be for 68 & 69 models? Should there be information in the breakdown of standard transmission or automatic, that would be appreciated, also?