Stock A/C Clutch Pulley Diameter5" or 6"? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**randy.powell** · 03-26-2017, 01:47 PM

Going to order a new compressor for my 71 C10 w/factory A/C and one of the questions I can't answer is the diameter of the clutch pulley. Options are one with a 5" or 6". If my truck wasn't 100 miles away I could just go out and measure it.... Searched the forums extensively but can't find that tidbit.
TIA,
Randy

**FirstOwner69** · 03-26-2017, 02:22 PM

I can't measure mine since I'm farther from my '69 than you are from your truck. But this may help. I found a new compressor (R12) on Craigslist for $50. However, it has a smaller pulley than my original. So, my guess is you want the 6" pulley. Here are pictures of my original and the new one for reference.

**Stocker** · 03-26-2017, 02:27 PM

If it helps, the OEM pulley on my '72 K20 is 5".

**Steeveedee** · 03-26-2017, 07:22 PM

Mine ('70 C20/402) is 6". Maybe the difference is BBC Vs SBC?

**tdangle** · 03-28-2017, 12:52 AM

I would think if you had low gears then the 6" would be better as it would turn the compressor a little slower. If you have high gear ratio a 5" would be better.

03-26-2017, 01:47 PM	#1
randy.powell Senior Member Join Date: Jun 2014 Location: Bushwood, MD Posts: 510	Stock A/C Clutch Pulley Diameter5" or 6"? Going to order a new compressor for my 71 C10 w/factory A/C and one of the questions I can't answer is the diameter of the clutch pulley. Options are one with a 5" or 6". If my truck wasn't 100 miles away I could just go out and measure it.... Searched the forums extensively but can't find that tidbit. TIA, Randy

03-26-2017, 02:22 PM	#2
FirstOwner69 Senior Member Join Date: May 2010 Location: Wisconsin & Arizona Posts: 4,838	Re: Stock A/C Clutch Pulley Diameter5" or 6"? I can't measure mine since I'm farther from my '69 than you are from your truck. But this may help. I found a new compressor (R12) on Craigslist for $50. However, it has a smaller pulley than my original. So, my guess is you want the 6" pulley. Here are pictures of my original and the new one for reference. Attached Images Last edited by FirstOwner69; 03-26-2017 at 02:28 PM.

03-26-2017, 02:27 PM	#3
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,497	Re: Stock A/C Clutch Pulley Diameter5" or 6"? If it helps, the OEM pulley on my '72 K20 is 5". __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay

03-26-2017, 07:22 PM	#4
Steeveedee Who Changed This? Join Date: Jan 2013 Location: Simi Valley, CA Posts: 10,087	Re: Stock A/C Clutch Pulley Diameter5" or 6"? Mine ('70 C20/402) is 6". Maybe the difference is BBC Vs SBC? __________________ ~Steven '70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper Simi Valley, CA Last edited by Steeveedee; 03-28-2017 at 04:32 PM. Reason: deleted unnecessary info

03-28-2017, 12:52 AM	#5
tdangle Senior Member Join Date: Mar 2005 Location: Jurupa Valley, Ca Posts: 1,209	Re: Stock A/C Clutch Pulley Diameter5" or 6"? I would think if you had low gears then the 6" would be better as it would turn the compressor a little slower. If you have high gear ratio a 5" would be better. __________________ Terry 1970 Custom Camper/C20 , GM Crate 350/7004R, Dana 60, factory AC



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