Shroud with or w/o AC - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Cmillet · 06-01-2014, 02:07 PM

Can I use an AC shroud on a non AC truck and vice versa? I've gone tons of previous post and can't find an answer. I have a 70 truck with a stock 307. Thanks.

ChevLoRay · 06-01-2014, 02:12 PM

I think the key to your question is where the blades of your fan are located. My understanding is that they need to be placed in the rearmost part of the shroud. If they are too far forward, they won't pull the air thru the radiator. Ditto if the blades are outside of the shroud.

Use of a long or short water pump and the spacers between the fan pulley and the fan itself, are what is going to affect where the fan is finally located.

haminator · 06-01-2014, 03:04 PM

I have always been under the impression that there are only 2 wheel and 4 wheel drive shrouds. No difference for A/c, however I may be proven wrong. Also there is the big block shroud. I'm not sure but a V-6 shroud sure looks like a big block shroud. Also DO NOT put a spacer behind a clutch fan, it will destroy your water pump in minutes, I learned this the hard way. I hope this rambling helped in some way.

Cmillet · 06-01-2014, 03:26 PM

Thanks guys. The lmc book has one with and w/o AC.

**FirstOwner69** · 06-01-2014, 03:41 PM

The original small block 2WD shrouds are two different depths. Otherwise, they are identical. The non-A/C shroud is 3/4" deeper than the A/C shroud. Therefore, the non-A/C shroud can be modified to took and function like an A/C shroud, but not the reverse. I believe the A/C shroud is actually the one to use if you have a 4 row radiator with or without A/C. As stated above, the proper shroud puts the fan blades in the correct position.

Here's a picture of the 2 back-to-back.

haminator · 06-01-2014, 03:54 PM

Ahh, I didn't consider the different radiator widths. Now I gotta look at my shrouds.

davepl · 06-01-2014, 05:20 PM

Yep, two factors at play here: fan thickness (since it has to be placed at a proper depth in the shroud hole) and rad thickness.

They're might be four shrouds:

Small block
Small block AC
Big block
Big block AC

There are also heavy duty cooling options but they probably use parts from the AC setup I'm guessing.

haminator · 06-01-2014, 06:09 PM

What do you know about the V-6 shrouds? I don't have a big block one to compare to but it sure looks like the pictures of ones I've seen.

**FirstOwner69** · 06-01-2014, 06:17 PM

I assume you mean I-6.
I think the original "shroud" on those was only a metal plate about a foot wide that extended from the top center of the radiator support to just above the fan. More of a safety feature than cooling aid.

haminator · 06-01-2014, 06:39 PM

Oh no I mean V-6. Such as GMC 305, 351 that was available in light duty trucks. I just got a 68 GMC C-30 with an Open Road Chassis mount camper with a 351 V-6. I still need to verify it is a 351 though.

**FirstOwner69** · 06-01-2014, 07:11 PM

Quote:

Originally Posted by haminator

Oh no I mean V-6. Such as GMC 305, 351 that was available in light duty trucks. I just got a 68 GMC C-30 with an Open Road Chassis mount camper with a 351 V-6. I still need to verify it is a 351 though.

Duh, I keep forgetting about those. I saw 2 in the local junkyard last year too.

06-01-2014, 02:07 PM	#1
Cmillet Registered User Join Date: Mar 2014 Location: Prairieville la. Posts: 135	Shroud with or w/o AC Can I use an AC shroud on a non AC truck and vice versa? I've gone tons of previous post and can't find an answer. I have a 70 truck with a stock 307. Thanks.

06-01-2014, 02:12 PM	#2
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	Re: Shroud with or w/o AC I think the key to your question is where the blades of your fan are located. My understanding is that they need to be placed in the rearmost part of the shroud. If they are too far forward, they won't pull the air thru the radiator. Ditto if the blades are outside of the shroud. Use of a long or short water pump and the spacers between the fan pulley and the fan itself, are what is going to affect where the fan is finally located. __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

06-01-2014, 03:04 PM	#3
haminator Registered User Join Date: Sep 2009 Location: Prescott Valley AZ Posts: 345	Re: Shroud with or w/o AC I have always been under the impression that there are only 2 wheel and 4 wheel drive shrouds. No difference for A/c, however I may be proven wrong. Also there is the big block shroud. I'm not sure but a V-6 shroud sure looks like a big block shroud. Also DO NOT put a spacer behind a clutch fan, it will destroy your water pump in minutes, I learned this the hard way. I hope this rambling helped in some way.

06-01-2014, 03:26 PM	#4
Cmillet Registered User Join Date: Mar 2014 Location: Prairieville la. Posts: 135	Re: Shroud with or w/o AC Thanks guys. The lmc book has one with and w/o AC.

06-01-2014, 03:41 PM	#5
FirstOwner69 Senior Member Join Date: May 2010 Location: Wisconsin & Arizona Posts: 4,839	Re: Shroud with or w/o AC The original small block 2WD shrouds are two different depths. Otherwise, they are identical. The non-A/C shroud is 3/4" deeper than the A/C shroud. Therefore, the non-A/C shroud can be modified to took and function like an A/C shroud, but not the reverse. I believe the A/C shroud is actually the one to use if you have a 4 row radiator with or without A/C. As stated above, the proper shroud puts the fan blades in the correct position. Here's a picture of the 2 back-to-back. Attached Images Last edited by FirstOwner69; 06-01-2014 at 03:48 PM.

06-01-2014, 03:54 PM	#6
haminator Registered User Join Date: Sep 2009 Location: Prescott Valley AZ Posts: 345	Re: Shroud with or w/o AC Ahh, I didn't consider the different radiator widths. Now I gotta look at my shrouds.

06-01-2014, 05:20 PM	#7
davepl Registered User Join Date: Aug 2006 Location: Redmond, WA Posts: 6,332	Re: Shroud with or w/o AC Yep, two factors at play here: fan thickness (since it has to be placed at a proper depth in the shroud hole) and rad thickness. They're might be four shrouds: Small block Small block AC Big block Big block AC There are also heavy duty cooling options but they probably use parts from the AC setup I'm guessing. __________________ 1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible

06-01-2014, 06:09 PM	#8
haminator Registered User Join Date: Sep 2009 Location: Prescott Valley AZ Posts: 345	Re: Shroud with or w/o AC What do you know about the V-6 shrouds? I don't have a big block one to compare to but it sure looks like the pictures of ones I've seen.

06-01-2014, 06:17 PM	#9
FirstOwner69 Senior Member Join Date: May 2010 Location: Wisconsin & Arizona Posts: 4,839	Re: Shroud with or w/o AC I assume you mean I-6. I think the original "shroud" on those was only a metal plate about a foot wide that extended from the top center of the radiator support to just above the fan. More of a safety feature than cooling aid.

06-01-2014, 06:39 PM	#10
haminator Registered User Join Date: Sep 2009 Location: Prescott Valley AZ Posts: 345	Re: Shroud with or w/o AC Oh no I mean V-6. Such as GMC 305, 351 that was available in light duty trucks. I just got a 68 GMC C-30 with an Open Road Chassis mount camper with a 351 V-6. I still need to verify it is a 351 though. Attached Images



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