[Mike Larsen]

This is in relation to the recent vibration post.

I removed the starter to get to the casting numbers so I can ID the year/place the block was made, so I can make sure I have the correct dampener on. (There was concern that I had a later model 289/302/351 block with the earlier (3-bolt) dampener. Can someone tell me what the casting numbers mean?
1st row (smaller numbers) 6C22
2nd row (larger numbers) OC 5AE-6O15E

I am guessing that it is a 66 casted in Cleveland.

Thanks, Mike

[Dave]

Going from memory (at Work), top numbers are casting date, March 22, 1966. Second row, don't know what the OC is but 5AE-6015E again shows a block of 1965 vintage at "E" production level. Not sure there even was a Cleveland plant in 1966.
Dave

[hurricane28]

my 302 engine code behind starter is DAD 6015 5K22. What does it mean?

[Ivy66GT]

I think you are missing a number or letter. But its an engine block cast October 22 (my birthday) possibly in 1975? The original questioner back in 2007 was actually seeing a screw head looking blob, not an O, before a casting number of C5AE-6O15-E. The C means 1960s but that block was indeed cast in Cleveland. Your casting number should have a similar format with a leading 'D' meaning 1970s.

I don't know if Dave is still around but the Cleveland foundry was making 289s long before Windsor. Most 'Windsor' small block engines were made in Cleveland. In 1966 they made 'Windsor' 289s in both Windsor and Cleveland.

[Jonk67]

Those are some odd numbers, I had to take a toothbrush and degreaser to mine to get the correct numbers. The first symbol should be a letter and the 2nd a digit:
C=1960's
D=1970's
next digit is year - C5 = '65, C7='67, D0='70, D2='72,etc.

Hurricane, I've never seen 3 letters, try cleaning it again I bet there are numbers there and Hi from Smyrna!
Here's a pic of my '67's block to give an idea: