my old D C book says 1972 was the year the bolt holes changed
Before you go modifying it to fit the dampner, I would make sure it is correct for your application. You never did state what you are working on, but I have never seen a pulley with spacing like that for a Mopar from the late 60's to mid 70's.
heres one from a 66,it looks like the double stamped pulley you have.