I have a 1972 Cutlass ( non-AC) that had a frame off 20 years ago.
Doubt the bad fan clutch I just pulled out was the original HD Thermal clutch.
FYI- the 350cu was "worked" ( big cam, bored & channeled, etc etc) so I want to make sure a put in another Heavy Duty clutch
( car also has a 3 row radiator that I am adding a shroud to.
Everyone in the Olds groups I am in says get a Hayden HD. I found 2 on RockAuto ( 2747 and the low profile 2947). I measured the one I pulled out, which matched up in depth with the low profile, but it looks nothing like it. The Hayden is clearly bigger in overall diameter, beefier?, However bolt pattern to water pump matches up. Look at pictures below.

Also, here is a link to the only HD clutch on the internet that looks like the one I just pull out; look at front and back. it's almost exact:
https://www.thepartsplaceinc.com/pro...diameter/64484

And here is a link to one I just got in from Jegs that looks a lot bigger than the old one ( even shaft is thicker)
https://www.jegs.com/i/Derale/259/22...g+Confirmation


old one on right; yeah I just noticed the shafts are different.

 

I used the Hayden 2705 for my 70 Cutlass with 455. It looks pretty close and a lot cheaper then the one you found.

https://classicoldsmobile.com/forums...-455-a-157790/

 

Was there a question somewhere?

I say bolt that fan clutch on and see how it performs.

 

So you have the Hayden 2705 which is a Standard clutch and not a Heavy Duty like the ones in W-30's and it keep's the motor cool?
I've actually been looking to add a HD clutch as my car runs hot in traffic

 

I use a 215046 (Carquest) standard duty - the 2 HD units you mentioned will also fit (be sure in any case to use the sleeve that they come with to ensure a proper fit onto the water pump stem

 

Thank you