1966 225 slant 6 Motor

Thank you and thanks for posting that photo of the ID # . Can I use that photo in my ad ? So many people have no clue that the letter A is 65 , B is 66 for these early slants .It's the easy way to just look and check the year when you're looking at a car to see if the motor has been replaced.
Can I use that photo in my ad ?

sure, if that helps, go for it.
Can I ask, why are you looking for a '66 slant only. The slants cross change over many years. One can get into the
crank register size, (pre and post '67) but there are work arounds for that.