Looking for info ? Cooling system !

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JTWard

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My 88 K5 Blazer was equipped with RPO VO2 "heavy Duty" cooling system. What was the different pieces included ibn this option ? I'm looking to add a heavy duty fan and clutch to it. Thank you !
 

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I think it meant a bigger radiator with more cores?
 

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No, I dont think VO2 was a heavy duty radiator. It well, slightly. It was a transmission cooler in the radiator. I think. Unless RPO VO2 changed from 1978 to 1988.

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1987 GMC Jimmy

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I’d like to know this, too, but if I had to guess, I’d say it came with a TH400, and that big boy needed the extra cooling. Whatever that entails... Mine w/a 700R4 doesn’t have this nor would I ever expect it to.
 

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My 78 I posted a picture of the list is a 1/2 ton 4wd with a TH350. The V02 option to my understanding is the trans oil cooler to the radiator, while the K04 was an auxillary oil cooler mounted in front of behind the radiator OR it was the tank above the trans cooler on the passenger side.
 

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V03 was a big block radiator, I think. Or diesel.
 

1987 GMC Jimmy

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Interesting. The only Blazer engine options after ‘82 are the 305, 350, and 6.2. The 250 was in there before, but I hope that was only for C-Blazers. I can’t imagine a K5 with that one.
 

AuroraGirl

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Interesting. The only Blazer engine options after ‘82 are the 305, 350, and 6.2. The 250 was in there before, but I hope that was only for C-Blazers. I can’t imagine a K5 with that one.
Why couldnt a K5 have a 250? Inline 6 are the way to go.

Broncos are revered with the 4.9 300.

But V02 is for trans. Did K5 blazer come with a TH400 at all?
 

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Why couldnt a K5 have a 250? Inline 6 are the way to go.

Broncos are revered with the 4.9 300.

But V02 is for trans. Did K5 blazer come with a TH400 at all?

I think it’d be fine in a 2wd because they’re relatively light, but it seems a bit meager in a 4x4. A 292 would have been a more reasonable option, but I’m assuming the weight/use of a 4x4 was the main thinking at GM because the 250 option went away when the 2wd models did. I think the 305 is a lackluster option for a 4x4, yet it stuck around till the end.

And yes, the TH350 was gone after 1986 so I’d guess that they switched to the TH400 for 1987-90, and either only had the 700R4 as an option in ‘91, or they used their remaining stock of TH400s since everything else was using 4L80Es that year. @Keith Seymore would know.
 

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My 88 K5 Blazer was equipped with RPO VO2 "heavy Duty" cooling system. What was the different pieces included ibn this option ? I'm looking to add a heavy duty fan and clutch to it. Thank you !

What are you working with, standard or reverse rotation belt system?
 

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For the fan and clutch, measure your shroud opening and get a fan that’s slightly smaller. For the clutch, Hayden is a good option among others. A heavy duty fan clutch is likely unnecessary, will be noisier, increase parasitic losses and decrease economy. A good standard duty one should be adequate.

if you’re serpentine, it’s likely reverse rotation. If v belt, standard rotation.
 

84K30

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I saw that someone suggested the RPO code in question was for a “big block” radiator. As seen below, my K30 came with a 454 but that code isn’t listed. I also have a 4 speed so maybe it is related to the TH400?

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AuroraGirl

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I saw that someone suggested the RPO code in question was for a “big block” radiator. As seen below, my K30 came with a 454 but that code isn’t listed. I also have a 4 speed so maybe it is related to the TH400?

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I just suggested that a "heavier duty" radiator would be for a big block or a diesel.
V03 was what I guessed might be related, but maybe its just a heavy duty cooling code which could be on any setup. my 78 1/2 ton K10 has a 400 and a TH 350 with V02. Its the transmission cooler in the radiator tank.
 

JTWard

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No, I dont think VO2 was a heavy duty radiator. It well, slightly. It was a transmission cooler in the radiator. I think. Unless RPO VO2 changed from 1978 to 1988.

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Many pardons please. VO2 is in fact a "HD Rad/Trans Cooler" I miss read it. Also my truck has both a serpentine, and a v belt, what can I determine about fan rotation ? I always assumed that engine rotation was based on looking from the drivers seat looking forward. As on a ship, everything is seen from the stern. So your right is always the starboard side and your left is always port side. So my Blazers engine rotation is counterclockwise ? Clockwise if looking at the engine from the front bumper ? Thank you !

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