question for the sYc hive mind please

[AnthonyS]

While digging, I found a stash of pulleys and came across this one that I've had a long time...

It's identical in dimensions to the famed 3742991 stamped steel SBC SWP HiPo single groove crank pulley... but it's cast iron, and heavy!

It doesn't look like it was made in a HS machine shop one day and it's drilled / balanced like I've seen other GM cast pulleys... it's a deep groove, same as the above referenced one. No markings.

Thoughts? After market, marine, implement, heavy truck, machinery application?...

Thanks in advance,
Anthony