Cylinder date code?

[bmh]

Here are photos of two different early front FL cylinders with stamped in casting numbers, if you look close you can see that the digits 120 line up a little different on each. I don't know if you can tell in the small picture files I am posting but the lines are too crisp to have been cast in. Also included photos of the oil return section of a front and rear from one of the pairs, note how shallow the fins are over this area. I am also throwing in a photo from an original paint , early 50 with the cylinders installed. Note the silver paint over the base studs and nuts. In going through my notes and photos it looks like these were in use part way through the 50 season. Hence my interest in date codes from the second style. When did they first appear?

[Robert Luland]

Boy's, I owe you all one hell of an apology for my stupidly. After edjomocating myself on this very subject I now realize that I have a set of 57 cylinders not 48. This has a good side since I own a 57 with cylinders on their last leg. Now for the good part. The last thing I want to see is any of you tripping over unwanted debris in garage or shop and getting hurt. So I’ve decided to pay whatever it takes to protect you from this awful fate. I NEED A SET OF 48 CYLINDERS! HELP! Bob