If you mean you don't know the year of the Cub, it is easy to find.
The serial number is stamped in the plate on the right side of the steering gear housing.
Sometimes the plate is painted over by someone, or the words are faded away and can't be read.
Below is a page from the 1950 Cub owner's manual showing where the plate is.
https://farmallcub.club/rudi/farmallcub.com/rudi_cub/www.cleancomputes.com/Cub/Cub Owner's Manuals/McCormick Farmall Cub Owner's Manual 1950/Page 02.jpg
Sometimes the plate is gone.
If the plate is there, use a light and look closely to find the number. If the plate is painted over, you can probably see the number in the position where it should be.
There is also 1800 stamped in the plate, that is the maximum engine RPM.
Below are pictures from TM Tractor parts of Cub serial number plates. The style of plates changed through the years.
Pic 1 was used beginning in 1947.
Pic 2 was used from 1950 - about 1956.
When you find the serial number, you can find the year in a Cub serial number list, or ask on here.
