'76 GMC 1 ton (454) radiator???

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OldBlueDually

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Gent's, I am trying to figure out what radiator to get for my truck and need some assistance.

My truck did not come with a radiator so I am trying my best to find a 4-core that will work, but I do not know the proper/stock dimensions of the radiator.

Can anyone give me some advice, or where to go?

Specifics of truck;
76 GMC Sierra Grande, C30/35 crew cab, 454, with A/C

So far, here is what I have found, but I am not sure what will work. What do you guys suggest?

This one below according to Amazon met all the requirements of the truck;

https://www.amazon.com/dp/B01MYUVC7...wVehicle=1&vehicleId=9&vehicleType=automotive

LMC part number 32-2945;

https://www.lmctruck.com/1973-87-chevy-gmc/cooling-system/cc-1973-87-radiator

RockAuto Ultra Power 730;

https://www.rockauto.com/en/catalog...54cid+v8,1406933,cooling+system,radiator,2172

Summit Racing radiators (a bit more $$$);

https://www.summitracing.com/search...eywordMatch&SortOrder=Ascending&keyword=4-row
 

bucket

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Do you currently have a stock fan shroud or top radiator mounting panel?
 

bucket

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Yes, I have both of those.

If you have the flat upper panel, you need the tall 19" radiator. If you have the upper panel with the big step down in it, you need a 17" tall radiator. Core thickness and tube design is kind of up to you.
 

sirweesarunch

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If you have the flat upper panel, you need the tall 19" radiator. If you have the upper panel with the big step down in it, you need a 17" tall radiator. Core thickness and tube design is kind of up to you.
I’m in the same boat as you , worse actually cuz i need engine oil cooler in mine. You need the largest radiator they sell. 19” tall 34 1/2” wide. I wanted brass. Found a radiator shop who ordered me one. Very difficult to find. $600. Mother—/// [emoji2959]. [emoji16]


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OldBlueDually

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If you have the flat upper panel, you need the tall 19" radiator. If you have the upper panel with the big step down in it, you need a 17" tall radiator. Core thickness and tube design is kind of up to you.

THANK YOU for that information!!! I have nothing to base it on. I do have a 4 core radiator from a 69 Olds, but not sure of its condition. I would rather put in a new and be done with it.

My 76 GMC parts truck (the green one) has that shorter radiator with the step down in the upper bracket. In my truck I do want the 4 core, because I plan to use the trans lines in it, and I plan to run AC on the truck some year.

My goal right now is to get this monster on the road!! AC can come later.


I’m in the same boat as you , worse actually cuz i need engine oil cooler in mine. You need the largest radiator they sell. 19” tall 34 1/2” wide. I wanted brass. Found a radiator shop who ordered me one. Very difficult to find. $600. Mother—/// [emoji2959]. [emoji16]

Holy balls man! However, at least you got what you want!!!!

I know the feeling of wanting something in particular. I FINALLY found shorty headers for my build for this truck (455 Olds), and they come out in the same stock position as the cast iron exhaust manifolds. They are $475 for the pair, but made of stainless, polished & a 1/2" flange....so it will last forever.

Regular headers I could get for half that price...
 

Bextreme04

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1997 K2500 Suburban 454 Radiator will fit and is the largest size you can find. It’s 4 core and has a huge transmission and engine cooler. $50 at most parts yards. They should be the same for any 1996-1999 3/4-1ton suburban or Silverado with a 454. The 2007-up Silverado dual electric fans are a perfect fit for this radiator as well. Just in case you wanted to go big. I got both for $100 total for the pair.

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OldBlueDually

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1997 K2500 Suburban 454 Radiator will fit and is the largest size you can find. It’s 4 core and has a huge transmission and engine cooler. $50 at most parts yards. They should be the same for any 1996-1999 3/4-1ton suburban or Silverado with a 454. The 2007-up Silverado dual electric fans are a perfect fit for this radiator as well. Just in case you wanted to go big. I got both for $100 total for the pair.

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NICE!! Would it fit a 76 though? I am looking for a direct bolt in & be done.

I plan to go aluminum, and to get a fan/clutch assembly on this.
 

Bextreme04

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NICE!! Would it fit a 76 though? I am looking for a direct bolt in & be done.

I plan to go aluminum, and to get a fan/clutch assembly on this.
Yes it will fit with no mods. It is the exact same size as the C30 454 radiator that was rare. There was a thread somewhere and I ended up sending a member here the original fan and clutch that came stock on my donor motor. It was a 9 blade reverse flow fan. I would see if I could find a 1996-99 suburban in a local junkyard and pull the whole shebang... radiator, fan, clutch, and shroud. Here’s some pics of the fan I sent out a few months ago. And a pic from the front of my donor. You can see how big around that fan is, the shroud fits level and should bolt up to the factory upper metal radiator bracket.
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OldBlueDually

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1997 K2500 Suburban 454 Radiator will fit and is the largest size you can find. It’s 4 core and has a huge transmission and engine cooler. $50 at most parts yards. They should be the same for any 1996-1999 3/4-1ton suburban or Silverado with a 454. The 2007-up Silverado dual electric fans are a perfect fit for this radiator as well. Just in case you wanted to go big. I got both for $100 total for the pair.

You must be registered for see images attach


Well I am to the point now I need to get one of these here and I took your advice and I gave a shout to the local yard I buy a lot of stuff from, they have a nice 4-core radiator from a '97 3/4 ton Chevy truck. They also have a 2009 Silverado dual electric fan too, he said one fan has 5 blades and the other 7...??

$65 for the radiator, and they leak check the radiator and make sure its all good. The dual electric fan setup is $60. Usually a 60 or 90 warranty on parts, but if I have this baby running in that amount of time I will be lucky. He said he was going to measure up the radiator for me too so I can verify a few things, but the dimensions he has are matching what @bucket posted above so I am sure it will work just fine.

Thanks again for the information & advice guys! Once I get it home I will drop it into place and see what it looks like.
 

Bextreme04

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Well I am to the point now I need to get one of these here and I took your advice and I gave a shout to the local yard I buy a lot of stuff from, they have a nice 4-core radiator from a '97 3/4 ton Chevy truck. They also have a 2009 Silverado dual electric fan too, he said one fan has 5 blades and the other 7...??

$65 for the radiator, and they leak check the radiator and make sure its all good. The dual electric fan setup is $60. Usually a 60 or 90 warranty on parts, but if I have this baby running in that amount of time I will be lucky. He said he was going to measure up the radiator for me too so I can verify a few things, but the dimensions he has are matching what @bucket posted above so I am sure it will work just fine.

Thanks again for the information & advice guys! Once I get it home I will drop it into place and see what it looks like.

Just a heads up, I laid mine in the core support since I have it apart for cleaning and engine replacement. It fits fine, but definitely needs some modification for the upper and lower radiator mounts. The fans will require some trimming on the lower mounts and some trimming of the shroud for different depths of the core and side supports. I can post some pics if it helps, but I still think it should work fine. I'm looking at various options but it looks like it should be very doable and should work well while looking good and almost like a factory installation.
 

OldBlueDually

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Just a heads up, I laid mine in the core support since I have it apart for cleaning and engine replacement. It fits fine, but definitely needs some modification for the upper and lower radiator mounts. The fans will require some trimming on the lower mounts and some trimming of the shroud for different depths of the core and side supports. I can post some pics if it helps, but I still think it should work fine. I'm looking at various options but it looks like it should be very doable and should work well while looking good and almost like a factory installation.


What modifications did you have to do on the upper/lower radiator mounts? I am not too concerned about modifying things within reason.

My entire engine bay is still open with no engine, so I have plenty of room to make things right the first time. I would rather put some sweat labor into something to help save some $$$$ up front.
 

Bextreme04

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What modifications did you have to do on the upper/lower radiator mounts? I am not too concerned about modifying things within reason.

My entire engine bay is still open with no engine, so I have plenty of room to make things right the first time. I would rather put some sweat labor into something to help save some $$$$ up front.

It is much wider, so I'll probably be taking the lower mounting bracket from the donor 97 and weld them onto the stock core support, also the upper needs to be further out to the sides. It kind of works with the stock lowers, but the mounts are meant to hold the tank ends and instead is on the core itself. I'll post some pics in a bit.
 

Craig 85

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I'm not sure about dimensions, but when you talk to the yard you may inquire about 2007 & up versions. GM offered a 9/7 bladed electric fan with the HD tow package. I know my 2010 Denali XL with a 6.2L had it.

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Bextreme04

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I'm not sure about dimensions, but when you talk to the yard you may inquire about 2007 & up versions. GM offered a 9/7 bladed electric fan with the HD tow package. I know my 2010 Denali XL with a 6.2L had it.

You must be registered for see images attach

Oddly enough the newer HD towing ones went back to the lower blade count. The one I have came from a 2013 2500 with the HD towing package and it is a lower blade count. The Silverado and suburban/yukon ones are slightly different too, just FYI. It might be that the suburban/yukon ones went to higher blade count to sacrifice a bit of flow for being quiter... but that is just a guess.
 

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