1969 and 1970 Chevy B car (…at a minimum).
I wouldn’t be surprised if it spans more model year/usages than that, but my charts start in 1969, and the format changed in 1971 making it less obvious.
This is how it was done in the days before Excel spreadsheets….
[img]<<GRAEMLIN_URL>>/wink.gif[/img]
K
