230 engine casting code

[tntleake]

Want to verify the 7*10*D is a 58 c123 built 7/10/58?
casting code is 366204R1 and sn is 48678

I also have a 200 with a c-123 casting code 354898R3 3*1*A serial number 6819 built 3/1/55?
Where can I find the cast code letters and corresponding year. I have went back in the forums with no luck
 

[mkirsch]

This subject comes up all the time. I'm surprised you couldn't find anything.

Anyway, all you have to remember is that 1955 is A. You can count back and forth from that, with the only exception being 1950 which used T, U and V.
 

[CNKS]

The first casting letters began in 1931 with A and ended in 1954 with Z. They started over with A in 1955. In the first group they are consecutive except that U and W were both used in 1951. Some controversity whether V was also used in 51, if so there were very few. The second group beginning in 1955 were mostly consecutive except a few letters were skipped. My latest tractor is a 1958 (D) I am not familiar with the later ones. The letters you gave for your two tractors are correct.