This is probably something you already know, but here goes anyway: the Chevy 6 engine was introduced in 1929. From then on Chevy published a current year 6 cylinder parts book and a separate 4 cylinder parts book that shows which 4 cylinder car parts they still stock. Over the years the 4 cylinder parts book was discontinued (can someone tell us the last year it was published?). By the 1940s the 6 cylinder car parts book was updated each year and would have a name like "1929 to 1946." That meant that it shows all the new 1946 parts and all of the older parts still available back to 1929. Each year some of the older parts would disappear. To be most useful, it is good to have a Chevy parts book that brackets your own car. So if you have a 1950 Chevy, try to find a "1929 to 1953" parts book. That will show if older parts will work on your car and if parts from a car a few years newer are useable too. If you have a 1929 Chevy and the only book you can find is for "1929 to 1953" it is still useful but it won't show every part for a 1929. (The 4 cylinder and early 6 cylinder parts books are reproduced and are available from several advertisers).
