Clutch Fan Question

[Mr70]

Yours took the Non pie-plate design fan clutch originally,#3857530 stamped CK,and has been discontinued some 30 years ago.It was superseded by clutch #3916141
But that's good news,as that's the same one the 65 Corvettes used,which means it most likely has been prone to be reproduced,and it has... HERE
There were two manufacturers making this Clutch,Eaton & Sweitzer.
Swietzer is known for the Bi-metallic thermostat,and Eaton the coil thermostat.
That's an Eaton on Ebay.
I have a Swietzer lying around,but it's by no means reliable anymore.
Both off those clutches measured up 2-3/4 deep,6" diameter with a 1-3/4 center.
You don't have to pay that Ebay price yet.Wait until LaborDay weekend is over & I can probably find you one less expensive & in your area.