Can you tell me what may cause this? I have a 383 Small Block Chevy in my 67 Camaro and have shredded 2 Crankshaft pulley's. Don't have any idea what is causing this. Any ideas?

 

Have you checked the parts driven by the belt to see if any are freezing up ,AC maybe, alternator etc.? Are you sure you have the right pully and it's not hitting something behind it?
I've been around Chevys for over 50 years and never seen one broken like that.
The 383 is a stroked 350 so maybe the crankshaft needs a different pully.

 

Thank you!

 

I've never seen it either in 50 years
I agree about checking all the accesories
but
I am thinking that particular pulley in the photo is a China one?
I hear tell about the cheap China pulleys doing exactly that
If a stock pulley, then I am wondering if the crank is out of balance enough to be causing it
What type of crank damper are you running? What crank?
Does it have a balance weight on the flywheel flange or a balanced crank?