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Old 01-08-2019, 06:39 PM   #1
kwmech
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Radiator Beef Up

My 91 suburban engine (350 tbi) tries to overheat when I tow in the hills around here, occasionally climbing into the 240 range. I'm thinking about converting/changing over to a 2wd 454 radiator which is wider by 5'' and a 4 core. Anybody done this conversion? I know I'll need a big block shroud and a new/wider pads, anything else?
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Old 01-08-2019, 07:39 PM   #2
Ziegelsteinfaust
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Re: Radiator Beef Up

You have to move some stuff around to make it work too.

I have been told the core support is different too, but I never compared.
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Old 01-08-2019, 10:03 PM   #3
kwmech
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Re: Radiator Beef Up

Looks like core support may be the same, there is another spot to the right for the diesel radiator
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Old 01-12-2019, 01:04 AM   #4
Zoomad75
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Re: Radiator Beef Up

The big block or 6.2 radiator will fit, but depending on which one you use you need the right brackets to hold it off of the core support. Obviously, you'll need the correct shroud depending on the radiator you intend on using.

I went from the stock 350 radiator to a 6.2 radiator with my 5.3 swap. It ran hot in really high ambient temps at low speeds. On the road or off road. Now with 6.2 radiator installed the highest I've seen the gauge was 200 in 113 degree heat on the Mojave road. The rest of the time it runs at 160 to 170.

The 6.2 stuff is harder to find for the top plate, brackets and shroud. One thing to keep in mind if you move to the bigger size is your evap canister *might* be in the way. I've got dual batteries in my K5 and that 6.2 radiator is really close to the driver's side battery.
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Old 01-12-2019, 02:53 AM   #5
kwmech
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Re: Radiator Beef Up

I've actually got an 85 truck here at the house with a 6.2 in it. Customer left it here 2 years ago with a bad engine... Hmmmm.
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Old 01-12-2019, 12:52 PM   #6
sweetk30
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Re: Radiator Beef Up

need more info on current setup .

185* or 195* t-stat ?

2-3 core ?

short or tall version ?

fan shroud or not ?

straight or clutch fan ?

std duty or hd towing / plowing clutch fan ?

how many blades on fan ?

jumping to the biggest rad possible is NOT always the best option from the start .

and a wimpy tbi 350 should not be overheating the system this much .
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Old 01-12-2019, 02:18 PM   #7
kwmech
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Re: Radiator Beef Up

Quote:
Originally Posted by sweetk30 View Post
need more info on current setup .

185* or 195* t-stat ?



and a wimpy tbi 350 should not be overheating the system this much .
Did not say it was over heating per se, but when towing it climbs into the 230-240 range on the grades---- 195 stat. All stock but starting to show wear and a little green around the seam of the tank. Hopefully will be starting a 400 sb build this year with the Dart block. Don't want to do the cooling system twice
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Old 01-12-2019, 03:42 PM   #8
sweetk30
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Re: Radiator Beef Up

i have run a gm 400sbc that was built to the hill . blue printed / balanced / knife edged crank and good cam and heads . use to be in a k10 with 1ton axles / 4.10 gear and 38" tires with th350 trans .

i tryed all combos of 3 core tall rad with and with out shroud and flex fan / clutch fan . she always did 210 98% the time .

most guys going in to the 4 core world tend to find its to much i have read .

might be a easy test and fix with a pusher fan infront of the rad on a temp switch in the intake by the t-stat .

but i understand were your coming from .
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Old 01-20-2019, 01:45 PM   #9
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Re: Radiator Beef Up

Have you considered just adding an high performance oil cooler?
Like maybe with an integrated fan?

If I was towing, and NOT overheating (as you are not) I would do two things:
1.) add an oil cooler - you could have a thermostat switch and also a toggle if you wanted.
2.) Transmission cooler with fan and a thermostat switch.

Both of these are "bolt" on items, no re-engineering needed like with your rad.

If you are set on the radiator upgrade I would go to dual electric fans!
I usually like to keep my stuff on the stock side, but I bought a rig with a 6.0 and elec. fans, and it works great. (and all GM parts too...)
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