Valve cover code number

[streetglide]

Can someone decipher this for me. I found the tag on the right valve cover. It looks like somebody in the past done a little head work and or changed to the valve covers? Here's the # 509N25 the letter B is also posted above this number. Are there any markings on the block some where other than the large 360 number stamped on the sides to tell me more info. I'm not even sure at this point if its the original motor....But it runs good....

[travisrda]

seems to me I remember my chiltons manual telling you how to decipher that number, I'll look it up for you tonight if you want me to

[streetglide]

Thanks...I gotta get one of those books!

[sungoesdown]

B
509N25

B- 0.010" oversize cylinder bore

5 would be either 1972 or 1982
09 means September
N- 360 2 bbl (5.9L, 70-91)

25th day

So I am thinking you have a 10 over bored 360 built on september 25, 1982

http://www.amcrc.com/tech/engine.html

http://www.ifsja.org/tech/motors/engcode360.html

[streetglide]

Thank you very much..!