Radiator Options

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LateOnTheBrakes

5.3-Swapped 86 CUCV
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What are you guys running for radiators on your LS swaps? My truck is a k30 that came with a Griffin radiator (8-00013-LS). I have tried different radiator mounts from the early and late model square bodies from LMC. I've also bought the what I assume are universal rated brackets from Griffin. None of the brackets fit well enough for me to trust them driving down the road.

Does anyone have experience with this radiator? Should I just ditch it for a better option radiator?

https://www.griffinrad.com/load_det...elect_Sub_Group_HorsePower=&key_id=8-00013-LS
 

Bextreme04

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I'm putting in a 97 K2500 Suburban 454 Radiator. It is significantly bigger than the stock large 4-core radiator that was originally in my truck. I cut the lower radiator support from the donor truck and am planning on welding it into the stock 1980 core support. The stock upper support works fine, but needs to be widened to use the correct mounts to hold the tanks rather than the core. I'm thinking about maybe cutting it right down the middle and welding in a fancy plate in the middle to make it look cool, but mostly stock at the same time.
 

LateOnTheBrakes

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I'm looking for OEM fit without any fabrication work. I think I need a thinner core radiator to fit with the factory mounts. Just don't know what's out there with provisions for steam hoses for the LS. I've seen talk of using the 454 radiator and upper mounts but I can't find any listings for that engine and radiator combo for the 86 model year.
 

LateOnTheBrakes

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The 4.3L brackets (13) fit pretty close. The 5.7L brackets (14) would need a 90* bend put in them to even be in the right place. How does the radiator fit from the factory? Should it be shorter and tuck under the core support? Should it be taller and closer to flush with the top of the core support?

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custodian

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I'm using a 2001 Silverado 5.3 stock radiator in my 73 C10. I've got the the bottom worked out, drilled a hole on each side and used stock rubber mounting pads. The top I've not got 100% figured out yet, but have an idea for the filler and mounting up top. I had to trim the fan shroud. The only reason I used this radiator was because I'm running the 01 4l60e and using the stock transmission cooler lines for 01.

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LateOnTheBrakes

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I wanted to go the 454 HD cooling route but the Spectra premium CU-730 seemed to be out of stock everywhere in the country. I found an equivalent at Napa and I'm pretty happy with the fit. It has a transmission cooler as well.
 

custodian

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I wanted to go the 454 HD cooling route but the Spectra premium CU-730 seemed to be out of stock everywhere in the country. I found an equivalent at Napa and I'm pretty happy with the fit. It has a transmission cooler as well.

I have the CU730 in the 85 C10 with a 350/700r4. Bought it years ago. I also have an all aluminum Champion radiator that I took out of the 73.
 

LateOnTheBrakes

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I have the all aluminum Griffin unit. Not too impressed. The 3" core makes it difficult when the biggest OEM unit was 2.25" deep.
 

RecklessWOT

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Excuse my ignorance, but with an all aluminum engine and a modern cooling system, wouldn't the need for an extra huge radiator go away? I feel like if the radiator for a K30 would probably be more than enough for any modern engine. If that's not quite enough, they sell plenty of big fancy aluminum radiators for stock applications. I was able to buy a 4 core welded aluminum radiator on Amazon for only a couple hundred bucks that was slightly bigger than stock but still fit in the stock mount holes, only thing I needed to do was slightly modify the brackets that hold the stock fan shroud in place. They made a zillion of these trucks, there's so much aftermarket stuff out there for them, surely you'll be able to find something that fits in there and will work with your fancy new engine
 

LateOnTheBrakes

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My engine is not all aluminum. It's a 5.3 with an iron block. And I wasn't going for something fancy. I spent less than $200 at Napa for the biggest radiator option available with the gas engine square body trucks. The diesel got a much wider and slightly shorter radiator. And I didn't want an all aluminum one. I got one with an aluminum core and plastic tanks on the end. I read a lot about the Griffin radiator leaking for a lot of people when it was fairly new. But either way I couldn't use rubber isolator mounts with the Griffin unit because it wasn't designed to fit in there. I bought the universal mounts from Griffin and they were just sheet metal brackets that they wanted me to do the fabricating work and sent foam tape to isolate. I wasn't about to spend the extra $500 for Griffin's shroud and fans.
 

TPISly-C10

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I keep my big oem diesel rad for my swap and buy adapter hose (after using bathroom stuff to get it done at first loll) for upper hose fitting :)

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Raider L

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@LateOnTheBrakes,

I bought a welded Alum. radiator for my truck in November of 2019. I searched for over a month every day and night online trying to find a radiator like the one I had had in my truck from the factory which was a brass and copper 3-core. I found one like it but it was $250. I called a radiator shop I had used for years and I asked him how much would it be to rebuild mine and he said about $250! Ha, ha,. So I embarked on a safari to find either a Alum./plastic one and looked for a month straight. What I had to do was measure mine and those shapes where the reservoirs that fit down in the rubber things the radiator sat down into had to be the same or close enough to be used.
I finally gave up because there just wasn't any my size in Alum. and plastic radiator so I ended up buying one of those welded Alum. radiators that fit perfect in those rubber things down there.

Can you find a stock radiator to use? Try and find a Brass and copper radiator 3-core like I had in my truck and it will provide more than enough cooling for your engine. What I had to do was go outside of my year truck. I started looking at vans, Cadillac's, big '70's-'80's Pontiac's, Oldsmobiles, and Buicks. I finally found a brass and copper radiator that was my size except it also had a oil coller made in it, it was for like a '86 Cadillac Coupe De Ville, I think. Start out with the factory radiator for the size engine you'll be using for your year truck. You might get lucky. These days everything for old trucks is being phased out of OEM for more modern equipment. And that equipment doesn't always fit like OEM either and that's the problem.
 

deviatedsheep

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brian
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K30 M1028 Military
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I put in a Radiator with E Fans from a 2008 Silverado in my K30. The Fans I got at a Pick and pull and the radiator I bought new for like $70 bucks. Made some spacers and a Rivenut gun.
 

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Bextreme04

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I put in a Radiator with E Fans from a 2008 Silverado in my K30. The Fans I got at a Pick and pull and the radiator I bought new for like $70 bucks. Made some spacers and a Rivenut gun.
I did similar. Finally got mine all in using the stock upper mount and modified the lower mounts. It’s a factory 97 K2500 454 radiator and 2011 K2500 dual electric fans. Fits great and its literally the biggest radiator you can possibly fit in here. It is right at the AC lines on one side and the air inlet on the other side. Stock 350 upper radiator hose and the stock 97 454 lower hose fit perfect.
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I also used the factory GMT-400 windshield washer tank and aux battery tray and the stock GMT-400 overflow bottle mounted on the drivers side wall where the original squarebody washer tank would have gone. The radiator was too wide for the stock overflow tank to fit between the main battery tray and the radiator.
 

deviatedsheep

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brian
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6.0 LQ4
I did similar. Finally got mine all in using the stock upper mount and modified the lower mounts. It’s a factory 97 K2500 454 radiator and 2011 K2500 dual electric fans. Fits great and its literally the biggest radiator you can possibly fit in here. It is right at the AC lines on one side and the air inlet on the other side. Stock 350 upper radiator hose and the stock 97 454 lower hose fit perfect.
Looks great, did the fans come out of a Gas or Diesel 2500?
 
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