Recommended Clutch Fan?

[Stocker]

Originally Posted by 1968_K20_4x4

Hello Stocker,

I have a question for you regarding your fan clutch. How did you determine that your K20 required a heavy duty unit, as opposed to the standard duty one?

I am looking to install a clutch fan set up in my '72 K20 as well, and all my research so far has pointed me to the Hayden 2705 fan clutch (Standard duty) as being correct for my truck. Did you go with the heavy duty unit because your truck is an A/C truck?
Mine has no A/C and manual transmission.

I am looking to use the 18 inch Derale 17118 fan as mentioned above, but I am not sure if I should go with the 2705 fan clutch or the Heavy duty 2747 as you are running. I am setting up my truck to haul a 22ft camper trailer on occasion.

Thanks for any input!

You're on the right track! My K20 does have factory A/C. Also, the original fan clutch was a heavy duty unit. Interestingly, my local NAPA store listed only a standard duty unit for my truck, but their information was incorrect. Either fan clutch should work well for you, although towing your camp trailer *might* require additional cooling. I would also suggest considering a 7-blade fan. Mine is factory, and is quiet.

If you haven't already seen it, Hayden's website shows the differences between clutch types. https://www.haydenauto.com/en/produc...-types/thermal