Does anyone know if a clutch fan was an option in '74? I purchased my car with a 4 blade mechanical. Not sure if this is correct either. Mine has the L65 engine if that makes a difference.
My 74 nova with a 350 sbc originally was equipped with a 19.5" - 7 blade clutch fan and a 21" diameter fan shroud.
The original fan with a replacement Hayden clutch shown in the image below.
View attachment 404921
A replication of the fan I am using can be obtained from Classic Industries (Part #3991431).
1971-1979 All Makes All Models Parts | 3991431 | 1971-79 OER Authorized 19-1/2, 7 Blade Fan | Classic IndustriesOER® Authorized reproduction fan blade which was installed as original equipment on various GM models with 19-1/2 diameter, 7 blade fan. Chevrolet Passenger Car Applications: 1971 Passenger with 36 Amp Except Police/Taxi 1971-74 Passenger V8 with C.A.C. 1971-74 Taxi/Police V8 Except C.A.C. 1975...www.classicindustries.com
I think the variation in fans had to do with the vehicle's original set-up from the factory... HD cooling, AC, etc.Thanks! That's exactly the route I am going. Just wasn't sure if it was "correct". Seems there's no real rhyme or reason for type of blade and whether it's mech or clutch.
I'm not familiar with the 6 blade derale fan... can you post a link to one.Do you think there is a real difference between that 7 blade and the 6 blade derale fan?
Well that says something, for sure!I think the variation in fans had to do with the vehicle's original set-up from the factory... HD cooling, AC, etc.
I will verify that my fan and shroud combo had no problem keep my 500 HP 400 sbc at 180° at long idle periods during the hottest summer days.
I'm not familiar with the 6 blade derale fan... can you post a link to one.
I'll take your suggestion on the 2747 clutch!I agree that the Derale Fan seems to be a universal fit.
Hard to say how the Derale fan would work compared to the 7 blade fan... maybe someone who has used the Derale fan will chime in.
Suggest doing a Goggle search on "Derale 17119 and read the reviews. Most reviewers seem to like this fan, but some complain that installing the clutch was tight... sometimes requiring filing that could throw off the balance of the fan.
What ever fan you decide to purchase, I do recommend the Hayden 2747 Clutch Fan. I am currently using this model. It's the heavy duty version... but it does not make any more fan noise that the standard version clutch fan (Hayden 2705). I have used both clutch fans.
Got the new fan yesterday. It looks really good. Great angle on the blades and should pull plenty of air and it feels very solid and sturdy.Sounds good!
Please keep us posted on how the Derale 17119 works out for you (fit, overall air flow, etc).
I'm sure it would provide useful information for those looking at options for economical clutch fans.
Well ill be dipped if I didn't strike a little gold while having some salvage yard therapy today during lunch. Just sitting in the bed of a '79 half ton pickup.Thanks for providing a detailed update on the installation of this fan!