Choosing a good radiator for LS Swapped 1985 K20

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Blackbeard44

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First time poster, long time browser of all the knowledge this forum holds.

I have swapped an LS from a 2005 Silverado into my K20, I'vebeen driving it for the last year with the stock 2005 radiator zip tied in place.

Iam looking tobuy an aluminum radiator/electric fan combo for it but I am having a hard time making up my mind.

some have 2 rows of tubes, some have 3 and alot don't specify.

Iliked the frostbite setup until you have to spend an additional $100 for the hose fittings.

Ihave a stock 6.0 now, but plan on a whipple supercharger this winte, I would likea cooling system capable of cooling 600+ HP.

what setupand from who do you reccomend??

I would like to thankany replies in advance as thisforum has helped me tremendously
 

eskimomann209

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I just used the square body’s radiator. You kept the pressurized radiator setup from the LS?
 

Blackbeard44

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I used everything out of the donor rig, when I bought the truck it did not have a motor/trans, or radiator or exhaust
 

Bextreme04

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I think I'll be using the radiator from the donor truck for my rig(not the actual one, but the same model). It is a 4-core aluminum that has the same height as the original square radiator and 34" core width. It's the stock radiator from a 1997 K2500 Suburban with the 7.4L. Has the engine cooler on the driver side and trans cooler on the passenger side, so you could run the factory LS cooler lines if you wanted too. I would highly recommend an engine oil cooler on a forced induction application.
 

Blackbeard44

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dont think my reply made it through the interweb, so I'll try again.

I am glad you mentioned an oil cooler, I had not though of that.

I will look into the 1997 big block radiator, although I was hoping to get something that was all metal, no plastic
 

bluex

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Blackbeard44

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I am interested to see what you have to offer,
 

Bextreme04

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Here’s a shot of the 454 radiator next to a stock 2011 Suburban 5.3 radiator. The hoses are the same size and in the same places, so you wouldn’t need to change anything there. It is almost exactly twice as thick and about 2” taller. I measured it and it is the exact same height as my stock, 4-core radiator in my 1980 K25, but about 5” wider.

@austinado16 had a thread where he ended up getting the full brass version of that radiator in his burb.

If it’s just the look of all metal you are going for, I get it... but if you are worried about reliability, that 454 radiator had 288,000 miles on it and is 23 years old. All new vehicles have the plastic radiator tanks and I can’t say I’ve ever had an issue. I’m planning on using a 2008-2014 factory dual fan system in mine with that suburban radiator and a rebuilt MPFI 454/4L80/NP205 setup. I’m really curious to see how well it cools.

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Blackbeard44

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I had no idea the later model radiators were that compatible, I do appreciate the info as well as pics, I am not knocking plastic radiators at all, my 2001 silverado that I have owned since 2003 still has original radiator in it with 365,000 miles and climbing, I just was thinking that an nice aluminum radiator would look good under the hood.
I have been looking all day and haven't found a setup that includes an oil cooler, I was ready to install a trans cooler, but now I would also have to mount an oil cooler.

is there any noticible cooling advantage with using a 2 core or a 3 core radiator, I am getting mixed info on suppliers websites, I though if I supercharge it I will be needing a 3 row, I still plan to tow a trailer ocassionally with the truck
 

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