Lower alternator brackets DSL stamped

[70LS6454]

I've seen a couple different types of stamping on these. Some just have the DSL and others have a circle around the DSL stamp. Does anyone know what the differences are, plant, year, etc?

Thanks,
Ray

[Enoch]

Ray,
I have several BB lower brackets stamped both ways but did not keep records of what years they came off.
Rich

[70LS6454]

Rich, I've seen the one with just DSL no circle on a 69 and 70. I wonder if was just the way they were stamped versus a year thing?

Ray