Clutch Fan
 

Is there a good aftermarket clutch fan for my 1971 GMC 4X4 with a 350 in it?

Re: Clutch Fan
 

four seasons makes great one look on summit

Re: Clutch Fan
 

Quite a few actually.... To be clear, do you need a clutch fan (fan blades), or a fan clutch (what the fan blades attach to)?

Assuming it's the clutch unit, your '71 is probably like my '72 K20. Factory 7-blade fan with a 2 1/2" pitch. If so, it should use a HD clutch like the factory one. HD ones have fins across the front, and standard-duty ones just have a ring of fins around the perimeter.

A few months ago I replaced my leaking OEM fan clutch with one from my local NAPA store. Made in Texas by Four Seasons, NAPA p/n 271303. It's a perfect fit.

Oddly, most aftermarket outlets don't list a HD unit for my truck. We had to look up a mid-to-late Seventies K30 to find the correct HD unit.

Good info here including differences between standard & HD,if you're interested: http://www.haydenauto.com/featured%2...s/content.aspx

Re: Clutch Fan
 

I should of been more specific, I need the Fan w/6 or 7 blades that will take a thermal clutch attached to it. I know I can get the clutch itself but can't find the fan.

Re: Clutch Fan
 

Stocker, thanks for the NAPA part# number also, I will check that one out.

Re: Clutch Fan
 

Forgot to add the Four Seasons part number to the above NAPA clutch I bought.... it's #2747.

Re: Clutch Fan
 

There's this but it's kinda spendy http://www.speedwaymotors.com/Dynaco...FQ9EfgodlrQB-A

A bit cheaper http://www.classicindustries.com/pro...arts/k193.html

Good luck, I hope ya find one that works for you. Local boneyards all cleaned out?

Re: Clutch Fan
 

Stocker, Also I think the 4 Seasons part#number is 36956, NAPA uses their own number I think, but I could be wrong.

Re: Clutch Fan
 

That's very possible.... I just got the p/n off the box it came in. It also had NAPA p/n 271303.

Re: Clutch Fan
 

Thanks for the info Stocker!

Re: Clutch Fan
 

I bought this one from Summit a few weeks ago https://m.summitracing.com/parts/der-17118/none/images. I'm happy with it

Re: Clutch Fan
 

Kelz702, Thanks for the info!

Re: Clutch Fan
 

OE fans come up for sale on the parts board from time to time as well.

Re: Clutch Fan
 

Hey guys, not to hijack this thread, but it's exactly the type of info I'm looking for. Couple questions, especially for you, Stocker, since our trucks are pretty similar:

1) Am I correct in assuming that the stock 7-blade fixed fan will accept a clutch unit? EDIT FOR FUTURE SEARCHES: Nope.

2) Stocker, how far does your fan clutch sit from the radiator? I've read elsewhere that a thermostatic clutch needs to be very close (like only 1-2") to the radiator in order to heat up properly and actually disengage. Want to change out my fixed fan (for HWY MPG) but as you all probably know the 4x4 engine sits further back and I want the clutch to actually work. My fixed fan is several inches from the radiator, essentially sitting just inside the shroud.

Thanks everyone for any info.

Re: Clutch Fan
 

Re: Clutch Fan
 

I don't believe that the 4x4 clutches sit that close to the radiator. Mine doesn't I know that much.

Re: Clutch Fan
 

Thanks for the reply. Kind of figured that too... but then I'm wondering if it actually warms up and disengages as it's supposed to?

Re: Clutch Fan
 

My fan sits roughly 7" from the radiator. The important thing is that it is more or less centered in the outlet area of the shroud, like Joey's fixed fan.


The Hayden link in post #3 explains when different type clutches engage / release etc. Not sure just how you'd actually check it, though.... depends on what problems you have, if any.

Re: Clutch Fan
 

Thanks Mike. Since yours apparently works okay I'll go with that Napa clutch PN you used, and decide on a fan to match.

Re: Clutch Fan
 

My replacement is a napa as well and it does work.