The VIN stamp I full understand on how it was done and why changes in the VIN stamping process was changed from full VIN to the year plant number. I know the tool that was used from January 1969 up to the Plants went to a Computer based information system. The only thing on a block I believe changes with the later blocks not 64s and 65s is the Casting Date. I should do a real strong comparison on all my block by the 1966 1969 and both 1970s all look the same. The 1965 block is slightly different. The only thing that changes is the Casting Date that is left when the block is cast. So I would think this piece could be taken out and the numbers changed via year, month day that is was cast. I think there would be in this area a piece that could be remove like I see on the 1965 block but will have to make sure of that and go out and see all the iron block I have or just do a google search for Hemi Block Casting Dates and use those pictures. I have a pictures of the 1963 block and a few 1970 blocks but were it is stored is gevin me a hard to to retrieve. So we could look back on this thread of start posting the location of the castin date to compare.