BBC - "original" shroud and radiator? - Another attempt at this - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**71CHEVYSHORTBED402** · 09-09-2016, 07:00 PM

I'm hoping to confirm whether or not I have the correct radiator. It's 24 years old, but it's in great shape, and I'd rather not spend the $500 for a simple replacement.

My dilemma is the return line on the radiator (see picture). As it sits it interferes with the edge of the shroud. The shroud is correct. On a side-note, it's mounted at the bottom using zip ties, but I wouldn't think that would matter. I'm guessing the problem is bad bushings, which may explain why I used zip ties.

You like the way they cut into the shroud when they replaced the radiator? That's a story in itself, and not a good one. Shame too, the top is the best I've seen. Now it's junk.

For what it's worth, this radiator is 34" wide. The side where the outlet is 3.1/4" from the outer edge of the radiator to the seam. The edge of the outlet is 2.1/8" from the outer edge of the radiator. Thank you.

davepl · 09-09-2016, 07:41 PM

My original radiator in my factory big block 1970 did not use a return to the radiator. The replacement unit I installed at restoration had a fitting there, but plugged.

Offhand, unless they varied wildly by year, I don't think that's a big block radiator. How many rows of tubes if you shine a light into the neck?

**71CHEVYSHORTBED402** · 09-09-2016, 09:45 PM

It's four core. On a side note, I got to looking at the "element" in the radiator for the transmission lines. Odd set-up. My lines weren't attached, I guess they figured an aux. was a better choice. It's currently at the dump.

Perhaps my set-up is wrong and I shouldn't have or be using that outlet? I'll look at the manual, see what's up.

**FirstOwner69** · 09-10-2016, 12:29 AM

I'm pretty sure the big blocks used the same 4 row radiator as the small blocks with HD cooling and/or air conditioning. If so, and based on my observations, the earlier years of this generation (such as my 69) had one of the heater hoses attached to the intake and one attached to the water pump. Later, one of the hoses was switched to the radiator, but I'm not sure which one. My guess is that it was a 1971 change which Dave's post seems to verify. Also, the 1972 service manual diagram implies that the routing might have varied depending on whether the truck had a manual, 350 Hydramatic or 400 Hydramatic transmission.

Hopefully, someone can chime in with more specific info.

**71CHEVYSHORTBED402** · 09-10-2016, 12:43 AM

Thanks Jim.

71-72 402, auto, A/C, 400 TH anyone? The outlet on my other truck (72) is plugged up, but the engine has had work, including a replacement manifold and shroud.

For what it's worth, the assembly manual for BBC:

Page 162: Appears to show top of the heater core to the radiator and bottom of the heater core to the manifold. I say appears because their "box" looks more like a radiator than a water pump. This is how my 71 was set up.

Page 388: Shows top of the heater core to the manifold and bottom of the heater core to the water pump.

Fun!

Aus69c20 · 09-10-2016, 06:59 AM

I've got a69 with a 396. I had the radiator recored and the radiator guy said it was still the original radiator. It doesn't have the return to the radiator.

**Dustmaker65** · 09-10-2016, 09:03 AM

Quote:

Originally Posted by 71CHEVYSHORTBED402

71-72 402, auto, A/C, 400 TH anyone?

I can take pics of my '72 later today...let me know.

**71CHEVYSHORTBED402** · 09-10-2016, 12:27 PM

Quote:

Originally Posted by Dustmaker65

I can take pics of my '72 later today...let me know.

If possible that would be great. A description might work in it's stead. Thank you.

Again for what it's worth, the Service Manual shows to the radiator. Reads "V-8 with Automatic Tans. (typical)"

**71CHEVYSHORTBED402** · 09-14-2016, 12:02 AM

My guess it's the wrong radiator. Even if the port was plugged it looks like it would rub the shroud. Tell you a story about that radiator, coming clean ha!..........This was a long time ago.

I was fired from a job. BS reason, but they didn't need one. My truck was at the shop for a new radiator, so I went to pick it up. In those days I did little more than oil changes. Anyway, I start the motor and oh (*(*^ the motor is fried. I didn't hardly question it, because I put too much trust into the shop. Figured it was just a bad day worse. Two days later my dog died, what a great weekend.

In those days I didn't appreciate or dive into the truck very much. It was years later I realized they cut the shroud up because of the new radiator, which is more reason to believe it's the wrong one (Vs bad bushings). I've also come to the realization it's likely they ran the engine without water.

**LockDoc** · 09-14-2016, 12:20 AM

Quote:

Originally Posted by 71CHEVYSHORTBED402

I'm hoping to confirm whether or not I have the correct radiator. It's 24 years old, but it's in great shape, and I'd rather not spend the $500 for a simple replacement.

My dilemma is the return line on the radiator (see picture). As it sits it interferes with the edge of the shroud. The shroud is correct. On a side-note, it's mounted at the bottom using zip ties, but I wouldn't think that would matter. I'm guessing the problem is bad bushings, which may explain why I used zip ties.

You like the way they cut into the shroud when they replaced the radiator? That's a story in itself, and not a good one. Shame too, the top is the best I've seen. Now it's junk.

For what it's worth, this radiator is 34" wide. The side where the outlet is 3.1/4" from the outer edge of the radiator to the seam. The edge of the outlet is 2.1/8" from the outer edge of the radiator. Thank you.

I'd be more than happy to pay shipping if you wanted to send that junky old shroud to me.....

LockDoc

*randy500* · 09-14-2016, 01:39 AM

Maybe this will help. I have 2 big block '72 trucks and one small block.
'72 1/2ton no A/C the large heater hose goes to the water pump.
'72 3/4ton with A/C the heater hose goes to the radiator.
'72 1/2 ton 350 truck with A/C, heater hose goes to radiator.
I have a 71 small block and can check the heater hose arrangement on that tomorrow, it didn't have the 4 core radiator though so I think it wouldn't apply here.

webfoot · 09-14-2016, 02:08 AM

Looks like a radiator from a mid 70s Van, they had the same rad inlet. I know because I used one in my chevelle since replacements were much cheaper.

**71CHEVYSHORTBED402** · 10-22-2016, 02:01 AM

Quote:

Originally Posted by randy500

Maybe this will help. I have 2 big block '72 trucks and one small block.
'72 1/2ton no A/C the large heater hose goes to the water pump.
'72 3/4ton with A/C the heater hose goes to the radiator.
'72 1/2 ton 350 truck with A/C, heater hose goes to radiator.
I have a 71 small block and can check the heater hose arrangement on that tomorrow, it didn't have the 4 core radiator though so I think it wouldn't apply here.

Thank you. Looks to me with A/C the hose goes to the radiator. My 72 doesn't, but it's got a new radiator and aftermarket intake. That said, seems to be some variables by year, etc. etc..

Thank you as well Webfoot. Could be.

And LockDoc, I'll keep you in mind. I'm not ready to get rid of it yet, but I won't be using it.

**Dustmaker65** · 10-22-2016, 11:50 AM

71CHEVYSHORTBED402, sorry for the late response, but my 72 402/auto w/o AC, has the heater hose going to radiator.

I have another radiator laying in my shop out of a 71 402/auto(not sure of options) that has the cap on the radiator inlet????

Not sure that helps you much with the other responses.

09-09-2016, 07:00 PM	#1
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,120	BBC - "original" shroud and radiator? - Another attempt at this I'm hoping to confirm whether or not I have the correct radiator. It's 24 years old, but it's in great shape, and I'd rather not spend the $500 for a simple replacement. My dilemma is the return line on the radiator (see picture). As it sits it interferes with the edge of the shroud. The shroud is correct. On a side-note, it's mounted at the bottom using zip ties, but I wouldn't think that would matter. I'm guessing the problem is bad bushings, which may explain why I used zip ties. You like the way they cut into the shroud when they replaced the radiator? That's a story in itself, and not a good one. Shame too, the top is the best I've seen. Now it's junk. For what it's worth, this radiator is 34" wide. The side where the outlet is 3.1/4" from the outer edge of the radiator to the seam. The edge of the outlet is 2.1/8" from the outer edge of the radiator. Thank you. __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assm. guide "kit" for restoring it from ground up. With assys, the guide accts for 1000s of OEM identifications and part numbers, all written in short order. 700+ images include assm, illust., charts, and points of interest. Much of the info. applies to all 67-72 GM trucks, and to a lessor degree all 67-72 GM vehicles. My build thread, and more on the guide https://67-72chevytrucks.com/vboard/...d.php?t=730025

09-09-2016, 07:41 PM	#2
davepl Registered User Join Date: Aug 2006 Location: Redmond, WA Posts: 6,332	Re: BBC - "original" shroud and radiator? - Another attempt at this My original radiator in my factory big block 1970 did not use a return to the radiator. The replacement unit I installed at restoration had a fitting there, but plugged. Offhand, unless they varied wildly by year, I don't think that's a big block radiator. How many rows of tubes if you shine a light into the neck? __________________ 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

09-09-2016, 09:45 PM	#3
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,120	Re: BBC - "original" shroud and radiator? - Another attempt at this It's four core. On a side note, I got to looking at the "element" in the radiator for the transmission lines. Odd set-up. My lines weren't attached, I guess they figured an aux. was a better choice. It's currently at the dump. Perhaps my set-up is wrong and I shouldn't have or be using that outlet? I'll look at the manual, see what's up. __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assm. guide "kit" for restoring it from ground up. With assys, the guide accts for 1000s of OEM identifications and part numbers, all written in short order. 700+ images include assm, illust., charts, and points of interest. Much of the info. applies to all 67-72 GM trucks, and to a lessor degree all 67-72 GM vehicles. My build thread, and more on the guide https://67-72chevytrucks.com/vboard/...d.php?t=730025 Last edited by 71CHEVYSHORTBED402; 09-10-2016 at 12:55 AM.

09-10-2016, 12:29 AM	#4
FirstOwner69 Senior Member Join Date: May 2010 Location: Wisconsin & Arizona Posts: 4,839	Re: BBC - "original" shroud and radiator? - Another attempt at this I'm pretty sure the big blocks used the same 4 row radiator as the small blocks with HD cooling and/or air conditioning. If so, and based on my observations, the earlier years of this generation (such as my 69) had one of the heater hoses attached to the intake and one attached to the water pump. Later, one of the hoses was switched to the radiator, but I'm not sure which one. My guess is that it was a 1971 change which Dave's post seems to verify. Also, the 1972 service manual diagram implies that the routing might have varied depending on whether the truck had a manual, 350 Hydramatic or 400 Hydramatic transmission. Hopefully, someone can chime in with more specific info.

09-10-2016, 12:43 AM	#5
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,120	Re: BBC - "original" shroud and radiator? - Another attempt at this Thanks Jim. 71-72 402, auto, A/C, 400 TH anyone? The outlet on my other truck (72) is plugged up, but the engine has had work, including a replacement manifold and shroud. For what it's worth, the assembly manual for BBC: Page 162: Appears to show top of the heater core to the radiator and bottom of the heater core to the manifold. I say appears because their "box" looks more like a radiator than a water pump. This is how my 71 was set up. Page 388: Shows top of the heater core to the manifold and bottom of the heater core to the water pump. Fun! __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assm. guide "kit" for restoring it from ground up. With assys, the guide accts for 1000s of OEM identifications and part numbers, all written in short order. 700+ images include assm, illust., charts, and points of interest. Much of the info. applies to all 67-72 GM trucks, and to a lessor degree all 67-72 GM vehicles. My build thread, and more on the guide https://67-72chevytrucks.com/vboard/...d.php?t=730025 Last edited by 71CHEVYSHORTBED402; 09-10-2016 at 01:47 AM.

09-10-2016, 06:59 AM	#6
Aus69c20 Registered User Join Date: Jun 2015 Location: Melbourne, Australia Posts: 231	Re: BBC - "original" shroud and radiator? - Another attempt at this I've got a69 with a 396. I had the radiator recored and the radiator guy said it was still the original radiator. It doesn't have the return to the radiator. __________________ John 69 c20, 396, th400, dana60, ps, ac

09-14-2016, 12:02 AM	#9
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,120	Re: BBC - "original" shroud and radiator? - Another attempt at this My guess it's the wrong radiator. Even if the port was plugged it looks like it would rub the shroud. Tell you a story about that radiator, coming clean ha!..........This was a long time ago. I was fired from a job. BS reason, but they didn't need one. My truck was at the shop for a new radiator, so I went to pick it up. In those days I did little more than oil changes. Anyway, I start the motor and oh ((^ the motor is fried. I didn't hardly question it, because I put too much trust into the shop. Figured it was just a bad day worse. Two days later my dog died, what a great weekend. In those days I didn't appreciate or dive into the truck very much. It was years later I realized they cut the shroud up because of the new radiator, which is more reason to believe it's the wrong one (Vs bad bushings). I've also come to the realization it's likely they ran the engine without water. __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assm. guide "kit" for restoring it from ground up. With assys, the guide accts for 1000s of OEM identifications and part numbers, all written in short order. 700+ images include assm, illust., charts, and points of interest. Much of the info. applies to all 67-72 GM trucks, and to a lessor degree all 67-72 GM vehicles. My build thread, and more on the guide https://67-72chevytrucks.com/vboard/...d.php?t=730025

09-14-2016, 01:39 AM	#11
randy500 Account Suspended Join Date: Jul 2016 Location: Tacoma, WA Posts: 6,873	Re: BBC - "original" shroud and radiator? - Another attempt at this Maybe this will help. I have 2 big block '72 trucks and one small block. '72 1/2ton no A/C the large heater hose goes to the water pump. '72 3/4ton with A/C the heater hose goes to the radiator. '72 1/2 ton 350 truck with A/C, heater hose goes to radiator. I have a 71 small block and can check the heater hose arrangement on that tomorrow, it didn't have the 4 core radiator though so I think it wouldn't apply here.

09-14-2016, 02:08 AM	#12
webfoot Registered User Join Date: Nov 2007 Location: Hermiston, OR Posts: 947	Re: BBC - "original" shroud and radiator? - Another attempt at this Looks like a radiator from a mid 70s Van, they had the same rad inlet. I know because I used one in my chevelle since replacements were much cheaper. __________________ *Running in place gets you nowhere fast.* -me 1968 GTO 4-spd covnvertible 1970 K-20 4-speed, factory AC.

10-22-2016, 11:50 AM	#14
Dustmaker65 Senior Member Join Date: Jan 2015 Location: Marquette Heights, IL. Posts: 1,135	Re: BBC - "original" shroud and radiator? - Another attempt at this 71CHEVYSHORTBED402, sorry for the late response, but my 72 402/auto w/o AC, has the heater hose going to radiator. I have another radiator laying in my shop out of a 71 402/auto(not sure of options) that has the cap on the radiator inlet???? Not sure that helps you much with the other responses. __________________ Jimmy Hoelzel



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