Hello you must be talking about the one on ebay. I can only offer the following.
It’s depth looks like a long pump this makes it 68 – 82
It’s shape looks like 68 – 74
If one is 6 1/4 in diameter it is a std low hp type and not a deep grove but may look like one
The ad says it is 7 1/8 in diameter so it is pre 74 and most likely an hp type.
Non smog so non california car?
GM type but model unknown.
They used larger diameter pulleys on high hp cars to turn the pump more slowly because of the increased rpm of hp engines. It also helps keep the belt on.
The extra groove is either for double alt pulley or p/s.
