Keith,
All coils that I’ve seen after 1969 are 4 1/2” and have either made in USA or made in Canada cast into the plastic top. Prior coils were 4 3/4 and had made in USA Printed in ink on the backside of the coil and not visible once installed. Also 69 and prior coils had bumps around the perimeter as shown in the circle. Also note that 69 prior coils have a positive and negative stamp on BOTH sides of the stud and later coils only have it on one side.
The current mopar coils are similar and have two positive & negative marks around the stud and do not have any made in USA or made in Canada markings!