Big Block A/C Crank Pulley Identification

[matthon]

Sorting out pulleys and need help with this big block pulley.

Bolt pattern is symmetrical so after 72, iirc.

It's heavy, and appears to have rubber in the back.

What is this from?

 

[E7polyhachett]

My guess would be probably be off a 400 or 440. Like you said 72 and later pulley. It could of been on C body, truck, or RV, maybe something larger, with A/C. If you go to swap meets or other place, you may happen see one, and ask them if they knew what their pulley was picked from. I hope you find what
it came from.

 

[72dustervs]

I think its pre 71, research the stamped number may help as

 

[Dana67Dart]

That stack looks just like the stack in pulled off a 66 383.

757

 

[matthon]

That stack looks just like the stack in pulled off a 66 383.

Does yours have that rubber-ish ring?
Or those 4 not fully drilled holes on the edge?

 

[Dana67Dart]

Does yours have that rubber-ish ring?

I don't recall but my photo it doesn't look like it. But... I do recall a 68 318 AC and PS did.

Or those 4 not fully drilled holes on the edge

Those are holes made to balance the assy, so each one will be slightly different in number or depth

 

[matthon]

I don't recall but my photo it doesn't look like it.

On mine it's on the back.

 

[townsend]

For further research search eBay:
mopar 757 pulley

 

[matthon]

Finding multiple descriptions and versions, some with the rubber, some without, some symmetrical bolt pattern, some not.

Guessing here:

A few factors apply.
71 cast/externally balanced crank, forged still produced.
72 went to symmetrical crank pulley bolt pattern.

Cast/externally balanced engines received the externally balanced harmonic balancer.

They also received the balanced crank pulley, at least the larger a/c pulleys.

Explains both symmetrical and asymmetrical pulleys like mine.

My guess is the balanced a/c pulley could be bolted on a cast/externally balanced crank, as well as a forged/internally balanced crank.

And that eventually to save $ Chrysler did just that and stopped production on non- balanced a/c crank pulleys.