Engine serial number changes to Plant/month,date/Type Designation in 1957.
http://chevy.oldcarmanualproject.com/chevyresto/57011.htm

I don't doubt that your 1's look like I's on your engine serial number. But I like this explanation from the camaro site below, "All date codes are 2 digits, always, so if it looks like the letter I it is still the number 1."
http://www.chevy-camaro.com/chevy-camaro-engine-suffix-code-help.asp

Some references list the block casting number 3837004 as 55-57.
http://clubs.hemmings.com/clubsites/chevytalk/GMhistory/cast.html

Your engine serial number uses 1957-69 form, as 1962C10 (Joe) and Bill have indicated above.

I agree with the others, a 57' assembled at the Flint plant on Oct 17.




"Nothing astonishes men so much as common sense and plain dealing." - Ralph Waldo Emerson