Can I install a big block radiator in my small block burb?

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austinado16

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Hi guys, new member here.

I've got a 1990 GMC Suburban SLE V1500 (small block 4x4).

The existing Modine copper/brass radiator is pretty clogged and not a good candidate for rodding out. Sounds like re-coring it would be close to the cost of new.

I don't want to put one of the cheap looking aluminum/plastic radiators in it. I've seen a Vista Pro, and was not impressed.

Figured if I'm spending the money on new, why not upgraded to the thicker version used with the big blocks. Correct me if I'm wrong (because I'm just learning about this) but it looks like there were 2 versions. One is the same width and height as the small block, just thicker. The other is longer, and thicker. So 28" core width, and 34" core width respectively.

My core support has the mounting areas for the longer version, and there's nothing in that driver's corner area, so I could install the long one.

Other than the plastic fan shroud and that metal top closing panel, and a new upper radiator hose (if I go with the long version) what other parts do I need?

Any decent sources for good brass/copper radiators? Just tried to use Partsgeek.com and wound up with a radiator completely not as pictured....not even close....and the upper filler neck area caved in by UPS.

Photos would be helpful too.

Thanks!

EDIT: Here's a shot of the 'burb. 276k on it now. Original engine. The original 700R4 lasted to 235k if you can believe that. We've had poor luck with rebuilts since then. The first went 150mi......yes, 150. The 2nd went 30k and we're now on the 3rd. All built locally using the original trans, but with all of the known upgrade components like online builders us. Hoping 3rd time's a charm.
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HotRodPC

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Welcome Todd !!!

I'm fairly certain it's a bolt in job. I know a guy who did the same thing to his Burb 4x4. In fact, I just got the radiator out of his Burb to put in my 454 truck that is leaking. Then the intent is to take the original radiator out of the 454 truck, have it rodded out, leak fixed where the tank meets the core, and use it in my small block 4x4 truck if it's worthwhile. If the radiator isn't in good enough shape for repair then it'll be scrapped, but I do beleive it's fine for repair.
Other option you might have is to find a 3 core all aluminum radiator. I hear those work very well, don't need the 4 core cuz the 3 core actually hold the same amount of water, and the aluminum discipates heat faster so an aluminum 3 core works better than a Copper/Brass 4 core. :shrug:
 

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austinado16

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Thanks for the welcome and the info!

I've thought about using a Griffin, and I guess I should call them. The photos I've seen for the "correct" radiator, don't appear to show a heater fitting in the top right corner. Called Summit Racing and they couldn't confirm either.

The burb isn't a daily driver, so it only leaves when it's time to tow or haul something, or when we're camping with the trailer in tow, and climbing 7,500' passes at 35mph on twisty 2-lane roads in 90+ temps. So since I'm spending $$, I'd like to make some improvement over the stock set up.

It came with a huge engine oil cooler on the left side radiator opening. I added a huge B&M/TruCool cooler to the right side, along with a fan out of a 2500 series.....
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89Suburban

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Welcome aboard, nice to see another Burb. Here is mine:

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I fear the day I lose my trans. I feels pretty good though. I got about 190K on her right now, all original, 350 TBI. Except for a set of new heads I put on a year ago. Now I'm just trying to fine tune her and fix a few bugs. Look forward to more pics of yours. :handshake:
 

HotRodPC

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Thanks for the welcome and the info!

I've thought about using a Griffin, and I guess I should call them. The photos I've seen for the "correct" radiator, don't appear to show a heater fitting in the top right corner. Called Summit Racing and they couldn't confirm either.

The burb isn't a daily driver, so it only leaves when it's time to tow or haul something, or when we're camping with the trailer in tow, and climbing 7,500' passes at 35mph on twisty 2-lane roads in 90+ temps. So since I'm spending $$, I'd like to make some improvement over the stock set up.

It came with a huge engine oil cooler on the left side radiator opening. I added a huge B&M/TruCool cooler to the right side, along with a fan out of a 2500 series.....
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Damn, that's a hell of a set up there. Is one of those a Trans cooler too?
 
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HotRodPC

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Ahh, I just noticed in your pic, you have the power squarebody mirrors too. Don't turn your head to long if one of us from the forum get around your Burb. Those might go buh bye !!! :rofl:
 

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Welcom to the forums! I agree, it should bolt in, as long as all of the outlets are in the same locations.
And as far as the different lengths, look at your radiator support, and the radiator brackets you have now, notice that there are some more threaded bolt holes outboard of each to accomodate the wider radiator.
 
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HotRodPC

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austinado16

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Partial success!

Nice Suburban with the Rallies. I'd have a set on mine 'cept it came with the factory alloys.

Re: the 2 coolers in my photo, the one on the right is the factory installed engine oil cooler. The one on the left with the factory big block pusher fan, is the 12x12x1.5" TruCool that I installed

Additional to those little gems, I've got a big B&M finned cast aluminum tranmission pan, that holds about 3 extra quarts, and it's bunged for the mechanical trans temp gauge that's mounted below the dash just forward of the 4x4 shift lever.

There's a similar finned cast aluminum rear diff cover that holds about 1/2 a quart extra gear oil. I've also got a huge rear sway bar, extra big rear springs, and the tension rod under the rear axle.

The most recent mod has been the Edelbrock TBI intake manifold, and a new distributor.

I do a lot of towing with it, and many times that winds up being up in the mountains at low speeds, so I've tried to "build" it to handle that.


In other news:

I was headed out of town to hit the big yards 30mi south of here, on the chance they might still have some old school GM iron, when I thought, "There's one local radiator shop I still haven't called." Pulled over, made the call....."Sure, I've got one of those big block radiators sitting right here. I want $150 for it."

So I now have the 2-1/2" thick version of my old radiator, and while I was out, I picked up the 454 fan shroud and top "closing panel" from a nearby yard.

Hopefully, in a few hours, I'll have some good news. Need to pull my t-stat and back flush the block and heater core so that I can start with fresh dexcool, distilled water, and a bottle of Water Wetter.

Here's a picture from a ski trip to Yosemite Nat'l Park a few years ago. Storm hit overnight, so this is the road on the way in. There was a sheet of ice under the snow to the point that you couldn't even walk around. Had to cable up all 4 for the entire day, and we were one of the few who didn't wind up in the ditch.
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I've also got a huge rear sway bar, extra big rear springs, and the tension rod under the rear axle.

The most recent mod has been the Edelbrock TBI intake manifold, and a new distributor.
Nice pic. I am very jealous of the rear sway bar. What is a tension rod? How do you like the new intake? Does all the factory stuff fit on it or you have to mod some things? Is it emissions legal? You got factory exhaust? Sorry for all teh questions, lol...
 

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Cool Story about Yosemite. Is that Mary Poppins sticking her head out the window of the Burb???
 

austinado16

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The radiator is in. Just bolts right in.....D'oh. My original hoses fit. I modded the lower rubber bushings that the tank seams set down in. Used the big block steel top "closing" panel, and the big block fan shroud.

The only thing that needs to be done is fan is mostly sitting rearward of the shroud opening, instead of inside it. So I'll need to make some sort of extension that screws into the existing shroud. Maybe I'll harvest a portion of the original shroud, or maybe I'll make something out of some 1/4" thick rubber sheet that I have, that's like mudflap type material. I'll have to think about it, and take some measurements.

Holds 3 gallons, including the overflow. I put in 1 gal of Dex Cool and 2 gallons of distilled, less the bottle of Water Wetter.

Re: the Edlebrock, yes, smog legal. Comes with the EGR ports. Everthing fit but the fuel line had to be rebent and I think I did a little bending on the throttle linkage brackets and cruise control business, and then afterward checked and reset the TV cable on the transmission, based on line pressure. Not sure that it was worth the effort, and I'm not sure that my butt dyno can tell the difference. I even played with the ignition timing a bit, running it up to 10* BTDC, and backing it off a little at a time, based on performance on a local 4mi long 6-7% freeway grade that's pretty brutal. I'm at 6* BTDC right now. I got a good deal on it via ebay, but it was quite a bit of work to install.

Re: the tension bar. I'm probably using the wrong term. It's a long shallow V shape with a saddle under the differential housing. It bolts to each end of the axle and is supposed to keep the axle from flexing under load. Probably worthless, but it was $20 at the yard, so how could I resist?

Re: the Yosemite photo, that's my daughter out front, and my Mom was with us for that trip....and hamming it up. Just prior to that photo, that Chipper parked behind us had the road blocked on a banked turn. He was trying to pull someone out of the ditch who'd put chains on the rear of a FWD car. The road had been fine, so we weren't cabled up yet, and weren't even in 4X4. We stopped in the line of traffic, right on the banked curve.......you can guess where this is headed. When traffic started to move again, I gave the throttle a soft touch (driven in snow plenty) and instead of moving forward, we just slide silently sideways, with me working the gas and steering trying to get the tires to hook up. Down the banked turn we slid, until we hit the snow plow bank. Fortunately, the bank was only about wheel high, so it stopped us without crushing the side of the truck. Had it not been there, we would have rolled, down into the forest. The Chipper walked down to us, asked me if we were alright, and then did the 5 step shuffle and fell flat on his back. The road was shear ice under the fresh layer of snow. I cabled up the left side, put 'er in 4X4 Lo, and drove up to the turn-out to do the right side...and take that photo.
 

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Are you a drummer by any chance?
 

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