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

[Rfish]

Looks like the heavy pulley’s we used to pull of my Uncles 427 powered dump trucks in the late 60’s early 70’s. The balancers were larger and even heavier than passenger cars…

[AnthonyS]

I was just thinking though, this is clearly for a SBC crank…

[PeteLeathersac]

'

57/58 'Vette Hi-Perf...
https://www.ebay.com/itm/17533857248...0AAOSw6gFim2o-

~ Pete

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[Lynn]

I would bet money it is for a "medium duty" truck with a small block. I bought an engine and trans out of a grain truck (C60) and it had a cast iron crank pulley, but was 3 groove, all deep groove.

All the BIG trucks (what Chevy calls "medium duty") that I have worked on (not many) had cast iron deep groove crank pulleys.
If I am wrong, I am sure one of the farm boys will straighten me out.

That Corvette pulley on ebay is stamped. I think Anthony is asking about the cast iron pulley.

[AnthonyS]

Thanks Pete, but Lynn is correct, I’m wondering about the unstamped cast iron one.