Upgrade: Installing the longer 2WD 3/4 ton 454 radiator

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austinado16

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I tow in pretty severe conditions, and have made a few modifications to help keep the coolant and transmission temps under control. A couple years ago I upgraded the original small block 3 row radiator to the bigger 4 row version that I saw offered in the 1/2 ton, 454 models. Nice, but I still had my eye on one day installing the much longer radiator that was used in the 2WD, 3/4 ton, 454 models.

Been trying to do some research and collect all the necessary parts, and finally, today was the day....

Some helpful part numbers and other misc. info:
-Radiator mount pads, 4 needed. LMC Truck part number: 32-0972 at $4.95ea
-Upper radiator hose. NAPA part number: 8396
-Lower radiator hose. Re-use the original small block's hose.
-Connections for transmission lines: Same as original small block radiator as well as the shorter 454 radiator.
-Spacer needed for the radiator fan on the small block: Approximately 3" thick and you'll need to come up with longer bolts for it in order to mount the fan to the water pump. I had already done this specific mod when I upgraded from the 3 row radiator and it's "deep" fan shroud, to the 454 4 row radiator, with the shallow shroud.
-I wound up rotating the driver's side horn 90 degrees, so that it wouldn't block the airflow through the upper-most hole that I'd cut into the core support.
-I used a Greenlee "Slug Buster" electrician's tool to cut the holes in the core support, and then cut between the holes with a jig saw, in order to create the oval openings. I purchased the slug buster kit about 2 years ago when I was installing a big natural gas, whole house generator.
-In the first photo, below, that's a stock GM pusher fan, in front of an 11"x11"x1.5" (B&M Super Cooler/TruCool) transmission cooler. The cooler on the driver's side is the original GM engine oil cooler.
-The stock radiator core dimension (not including the tanks) is 19" x 28". The longer radiator is 19" x 34" and about 40" total width.
-Transmission cooler in the right radiator tank can be about 8" tall, or 11" tall. The radiator I'm installing has the 11" trans cooler. It also has the engine oil cooler, in the left tank, which I won't be using.

Core support before installation:
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Cutting the outer air flow holes:
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Cutting the inner core support air flow holes:
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Comparing the 454 standard radiator and shroud to the longer versions:
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Installation complete:
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Final inspection and ready for a test drive:
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da_raabi

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Wow, very nice writeup. I imagine that monster will keep that 350 cool no matter what!

I guess I didn't realize there were different size radiators. Believe it or not I think I may actually have the shorter rad on my C30. Looking at the pic below I think you can see the wider mounting holes. Interesting. I would have thought a Camper Special 2wd with the 454 would have had that biggie rad.

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GTME94

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. I would have thought a Camper Special 2wd with the 454 would have had that biggie rad.

I thought that too but mine appears to have the smaller one also.

Todd, what year/combo truck did you get your parts from?
 

austinado16

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Thanks for the kind words on the write up.

I started out with all the parts off a 1989 Suburban R2500 (454/2WD). But ultimately, the radiator I installed is more of the 6.2 diesel version with the much larger trans cooler, and the big driver's side tank that contains an engine oil cooler (that I won't use), but it has the small diameter top and bottom hose flanges that fit the standard gasoline engine hose diameters.

I'm no authority on any of this, so all I can go by, is what I've seen in photos on ebay or CL, where people were selling square bodies, and they had this...or that...radiator.

For example, my 1/2 ton/4x4/350 'burb, got the short radiator with only 3 rows, so it was also the skinniest radiator. I've seen 3/4 ton, 4x4, 'burbs that had 454s with the short, 4 row radiator, and shallow fan shroud like you see in my comparison photo......which is the radiator that I initially upgraded to.... or if they were 3/4 ton 350s, they got the short/thick radiator with the deeper fan shroud.

Wew.....catch my breath.

Anyway, it appears this longer radiator was 3/4 ton, 454 and 2WD only, and maybe only offered in the 'burbs and maybe duallies? I don't know if the normal pickups ever got them.

Also, if it helps anyone considering the upgrade, the 6.2 radiator and shroud will fit, with one exception. Some of the 6.2s have larger coolant hose flanges, so look out for that. You can always get a radiator shop to swap your tanks onto a 6.2 core if you can't get the version with the smaller flanges.

I got lucky and a local old school radiator shop had a brand new/old stock, "long" radiator. It had the smaller coolant hose flanges, and for some reason, had the much larger (11" vs. 8") transmission cooler.

If anyone's interested in upgrading, I have enough parts to do one more conversion, and the radiator was just rebuilt locally, last week. PM me. Paypal friendly, and willing to ship FedEx Ground. You would simply need to purchase a new top hose, and 4 new mount pads, unless your mount pads are really nice.


Additional upper hose reference numbesr:
-Gates W0133-1688421 (this hose has the bend in it, like the NAPA hose shown in my photos above)
-AC Delco AC26152X (this hose runs straight across the fan shroud, exactly like the OE hose would have)
 
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89Suburban

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Nice write up and information Todd. Thank you.
 

austinado16

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You have to watch out for what kind of radiator is being offered. Your link shows an aluminum core/plastic tank version.

The copper/brass versions are sold by "Spectra" and "ProRad" via sites like autopartswharehouse.com Look up: 1989 Suburban R2500 7.4L And that radiator will have the correct hose fittings; probably something like 1.5" and an 8.5" transmission cooler. If you look up the 6.2 version, you may not get a version with hose flanges that will fit your hoses.

The 2 shroud pieces are NLA. I checked dealer stock, nationwide last week, both through the local Chevy dealer and the GMC dealer. Nothing. So it's wrecking yards only.

I have one radiator, freshly rebuilt, both shroud pieces, and both upper mounts.
 

MikeB

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That's some nice engineering, man! Makes my conversion from 250 six radiator to 305/350 V-8 radiator seem like a piece of cake. Although choosing the right radiator, fan shroud, and top brackets (from crappy on-line catalog descriptions) wasn't quite as easy as eating cake.
 

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what would it cost to get the spare radiator set up from you?
 

austinado16

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PM me for the details. Or email me directly at: austinado16 at cs dot com
 

austinado16

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Finally had a chance to get the camper out and tow with the new radiator. Engine coolant temps are rock steady, even climbing the long mountain grades where we always camp. Transmission temps performed similarly where normally I'd always see about 205-210F, it was running at 190F.

Nice improvement over the shorter versions of the radiator that I've previously been using.
 

1973c10

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Finally had a chance to get the camper out and tow with the new radiator. Engine coolant temps are rock steady, even climbing the long mountain grades where we always camp. Transmission temps performed similarly where normally I'd always see about 205-210F, it was running at 190F.

Nice improvement over the shorter versions of the radiator that I've previously been using.

Very cool :cheers:
 

Camar068

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Nice upgrade, I like the license plate platform you got there also. You make it or aftermarket?
 

austinado16

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They're kinda "old school" and called: "Fold-A-Way" License Plate Step. They come up on ebay pretty regularly.
 

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