4x4 Radiator Shroud Question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**ohboy321** · 01-17-2020, 02:31 PM

Did all 67-72 4x4 trucks have the 4x4 specific radiator shroud?

My 67 with a 327 currently has the shorter fan shroud. I haven't had any overheating issues in the few years I've owned it, but if it is supposed to have one I may work on doing that to prevent issues in the future.

When looking at my current shroud, I can see where having a deeper (by 3"?) one would work better.

Thanks,
Steve/NH

**Stocker** · 01-17-2020, 04:38 PM

Can't say for sure, but I bet they all came with the deeper shroud. For maximum efficiency, the fan blades should be right at the end of the shroud. I have read half-in and half-out is best, or just inside the end of the shroud. If yours is 3" away, it can't be pulling all its air through the radiator as it should.

**ohboy321** · 01-20-2020, 09:59 AM

The shroud and radiator are currently out of the truck, but it may be even more than 3 inches between the fan and the outside edge of the shroud.

I have read that the 4x4 motors were set back several inches compared to the 2WD trucks, which explains the different shrouds being used. So now I am thinking that all 4x4s would have used them.

My truck was made up from both 4x4 and 2WD trucks, so that would explain how it ended up with the shorter shroud.

As I mentioned, I haven't had any overheating issues yet, but I haven't sat in any long summer traffic backups or moved any heavy loads either.

**jamie72** · 01-22-2020, 10:58 PM

the motor on 4x4s is farther back than 2x4s, so they do have a specific shroud just for 4x4s.

646870SS · 01-22-2020, 11:59 PM

Here is the NOS one I put on my truck (showing sticker) - I can take a picture of the installed shroud (fan side) and check the distance on my '72 4x4.

**ohboy321** · 01-23-2020, 03:00 PM

Thanks for the picture of the label 646870SS, with the part number I did a little more research and that would be the correct shroud for my 67. I was able to verify it on GMPartsWiki here: http://www.gmpartswiki.com/getpage?pageid=21326 (starts at bottom of page).

Below is a picture of what I have now, and based on comments it is clear that I need the deeper shroud. One of the tabs is broken and I was going to repair it before putting it back in, but now I think the best thing to do is track down the OEM part.

Thanks to all for the help.

**Stocker** · 01-23-2020, 04:04 PM

Quote:

Originally Posted by ohboy321

Below is a picture of what I have now, and based on comments it is clear that I need the deeper shroud.

Yep, you sure do..... that appears to be a shroud for a 2WD truck.

Have you considered also adding a clutch fan? Well worth it IMO. If you're interested you can search for more info, or if you like I can pass along a few details for you.

646870SS · 01-23-2020, 05:54 PM

Here are the pics of mine. It is an original 4x4 truck with the NOS fan shroud. The one photo looks deceiving - the fan is in the shroud about 3/4" total so it is tucked in but this way it draws air with all that room in the front - the fan being so far back - it doesn't stick out from shroud. Hope this helps. I am not running a clutch fan, just the original one and it stays very cool. It is an air conditioning truck as well. Also running the original fan spacer - I think it is an 1-3/4".

**jamie72** · 01-23-2020, 10:49 PM

lmc sells them, if you were closer i got 2 extras, but shipping would kill the deal.

**ohboy321** · 01-24-2020, 09:17 PM

Those pictures are great 646870SS. I'm now surprised I haven't had any issues with overheating with the wrong shroud in place.

Stocker, no, I haven't considered a clutch fan for my truck, although I am familiar with the advantages. I have already media blasted and painted the one I have, so for now I will just concentrate on getting the correct shroud.

I'll be posting a WTB as soon.

tim_mc · 01-27-2020, 12:40 PM

I used a 4/4 shroud since my V8 is mounted in the 2WD straight 6/4x4 SBC location. My Derale 17118 18" 6-blade clutch fan fits perfectly. Shroud is LMC P/N 32-2826.

**jmader** · 01-27-2020, 10:17 PM

Quote:

Originally Posted by jamie72

lmc sells them, if you were closer i got 2 extras, but shipping would kill the deal.

How is the quality of the ones from LMC? I have an aftermarket from classic industries I don’t really care for. It’s more of a hard fiberglass than plastic.

tim_mc · 01-28-2020, 09:04 AM

I'm happy with my LMC shroud. The mounting holes lined up well, and the plastic is rigid enough to keep it's shape.

01-17-2020, 02:31 PM	#1
ohboy321 Senior Member Join Date: Aug 2015 Location: Dunbarton, NH Posts: 276	4x4 Radiator Shroud Question Did all 67-72 4x4 trucks have the 4x4 specific radiator shroud? My 67 with a 327 currently has the shorter fan shroud. I haven't had any overheating issues in the few years I've owned it, but if it is supposed to have one I may work on doing that to prevent issues in the future. When looking at my current shroud, I can see where having a deeper (by 3"?) one would work better. Thanks, Steve/NH

01-17-2020, 04:38 PM	#2
Stocker 20' Daredevil (Ret) Join Date: May 2003 Location: Jefferson State Posts: 13,495	Re: 4x4 Radiator Shroud Question Can't say for sure, but I bet they all came with the deeper shroud. For maximum efficiency, the fan blades should be right at the end of the shroud. I have read half-in and half-out is best, or just inside the end of the shroud. If yours is 3" away, it can't be pulling all its air through the radiator as it should. __________________ - Mike - 1972 K20 LWB 350/350/205 RIP El Jay

01-20-2020, 09:59 AM	#3
ohboy321 Senior Member Join Date: Aug 2015 Location: Dunbarton, NH Posts: 276	Re: 4x4 Radiator Shroud Question The shroud and radiator are currently out of the truck, but it may be even more than 3 inches between the fan and the outside edge of the shroud. I have read that the 4x4 motors were set back several inches compared to the 2WD trucks, which explains the different shrouds being used. So now I am thinking that all 4x4s would have used them. My truck was made up from both 4x4 and 2WD trucks, so that would explain how it ended up with the shorter shroud. As I mentioned, I haven't had any overheating issues yet, but I haven't sat in any long summer traffic backups or moved any heavy loads either. __________________ Steve/NH 1967 K10 327 Short Bed Stepside 2008 F350 Power Stroke 2007 BMW X3 2020 BMW 540xi 1995 Harley FLSTC

01-22-2020, 10:58 PM	#4
jamie72 Senior Member Join Date: Apr 2000 Location: madison indiana Posts: 3,840	Re: 4x4 Radiator Shroud Question the motor on 4x4s is farther back than 2x4s, so they do have a specific shroud just for 4x4s. __________________ jamie72 72 BB cheyenne -- Restoration getting started.. member #807 http://www.myspace.com/whitetailobsession www.antlertalk.com

01-22-2020, 11:59 PM	#5
646870SS Registered User Join Date: Jun 2013 Location: Minerva, Ohio Posts: 56	Re: 4x4 Radiator Shroud Question Here is the NOS one I put on my truck (showing sticker) - I can take a picture of the installed shroud (fan side) and check the distance on my '72 4x4.

01-23-2020, 03:00 PM	#6
ohboy321 Senior Member Join Date: Aug 2015 Location: Dunbarton, NH Posts: 276	Re: 4x4 Radiator Shroud Question Thanks for the picture of the label 646870SS, with the part number I did a little more research and that would be the correct shroud for my 67. I was able to verify it on GMPartsWiki here: http://www.gmpartswiki.com/getpage?pageid=21326 (starts at bottom of page). Below is a picture of what I have now, and based on comments it is clear that I need the deeper shroud. One of the tabs is broken and I was going to repair it before putting it back in, but now I think the best thing to do is track down the OEM part. Thanks to all for the help. Attached Images __________________ Steve/NH 1967 K10 327 Short Bed Stepside 2008 F350 Power Stroke 2007 BMW X3 2020 BMW 540xi 1995 Harley FLSTC

01-23-2020, 05:54 PM	#8
646870SS Registered User Join Date: Jun 2013 Location: Minerva, Ohio Posts: 56	Re: 4x4 Radiator Shroud Question Here are the pics of mine. It is an original 4x4 truck with the NOS fan shroud. The one photo looks deceiving - the fan is in the shroud about 3/4" total so it is tucked in but this way it draws air with all that room in the front - the fan being so far back - it doesn't stick out from shroud. Hope this helps. I am not running a clutch fan, just the original one and it stays very cool. It is an air conditioning truck as well. Also running the original fan spacer - I think it is an 1-3/4".

01-23-2020, 10:49 PM	#9
jamie72 Senior Member Join Date: Apr 2000 Location: madison indiana Posts: 3,840	Re: 4x4 Radiator Shroud Question lmc sells them, if you were closer i got 2 extras, but shipping would kill the deal. __________________ jamie72 72 BB cheyenne -- Restoration getting started.. member #807 http://www.myspace.com/whitetailobsession www.antlertalk.com

01-24-2020, 09:17 PM	#10
ohboy321 Senior Member Join Date: Aug 2015 Location: Dunbarton, NH Posts: 276	Re: 4x4 Radiator Shroud Question Those pictures are great 646870SS. I'm now surprised I haven't had any issues with overheating with the wrong shroud in place. Stocker, no, I haven't considered a clutch fan for my truck, although I am familiar with the advantages. I have already media blasted and painted the one I have, so for now I will just concentrate on getting the correct shroud. I'll be posting a WTB as soon. __________________ Steve/NH 1967 K10 327 Short Bed Stepside 2008 F350 Power Stroke 2007 BMW X3 2020 BMW 540xi 1995 Harley FLSTC

01-27-2020, 12:40 PM	#11
tim_mc Registered User Join Date: Jan 2019 Location: St Peters, MO Posts: 433	Re: 4x4 Radiator Shroud Question I used a 4/4 shroud since my V8 is mounted in the 2WD straight 6/4x4 SBC location. My Derale 17118 18" 6-blade clutch fan fits perfectly. Shroud is LMC P/N 32-2826. Attached Images __________________ 1967 C20, 350 SBC w/Comp roller cam, 700R4 w/3.42 posi, PS, 4-wheel PDB, Old Air AC & GM Tilt column.

01-28-2020, 09:04 AM	#13
tim_mc Registered User Join Date: Jan 2019 Location: St Peters, MO Posts: 433	Re: 4x4 Radiator Shroud Question I'm happy with my LMC shroud. The mounting holes lined up well, and the plastic is rigid enough to keep it's shape. __________________ 1967 C20, 350 SBC w/Comp roller cam, 700R4 w/3.42 posi, PS, 4-wheel PDB, Old Air AC & GM Tilt column.



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