What year is my 20? Can anyone tell me.

[71kidcasper]

I have a 20 I/O that I am restoring and turning into an outboard. So far I have cut out the deck. My question is how do I tell what year my boat is? I understand that the stingers changed between 1969 and 1970. My boat has no plate with a year and the numbers on the outside of the transom are worn so bad that I can't make them out. I would like to post pictures but I don't have my own web site. If anyone can tell me the difference in stinger design between 69 and 70 it would really help alot.