Clutch Fan

[18Z]

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

[hjewell2]

four seasons makes great one look on summit

[Stocker]

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

[18Z]

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.

[18Z]

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

[Stocker]

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

[Stocker]

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?

[18Z]

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

[Stocker]

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

[18Z]

Thanks for the info Stocker!

[kelz702]

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

[18Z]

Kelz702, Thanks for the info!

[57taskforce]

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

[joeydurango]

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.

[demian5]

http://www.truckandcarshop.com

[57taskforce]

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

[joeydurango]

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?

[Stocker]

Originally Posted by 57taskforce

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

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.

Originally Posted by joeydurango

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?

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.

[joeydurango]

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

[57taskforce]

Originally Posted by joeydurango

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

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