Correct Radiator

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custodian

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I've switched from the 6.2 diesel to a SBC 350 in my 85 C10 2WD, AT.

I now need to find the correct radiator that will fit. I've found two: Spectra 716 and the Spectra 730.

I've even looked at the C20 radiators.

Any suggestions would be helpful or another part number to check out.
 

Vbb199

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The 6.2 radiator would do a better job cooling, but if it's doesn't have port for the AT, then I guess you gotta do something else.
 

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OK the only good thing about a chevy diesel is the big radiator it came with. keep it. no matter what motor you choose to run there is no such this as too much cooling. Most square bodies would benefit from better cooling . OOH sh!t the deisel guys are going to go off now lol .
 

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The radiator was missing when I bought the truck. The radiator support has three spots to mount radiators of different lengths (side to side).

The 6.2 radiator had the trans cooling lines on the opposite side if I remember right. The old cooler lines I removed ran under the motor to the drivers side. I bought a standard cooling line set for the SBC.
 

Frankenchevy

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The diesel rad will have bungs for fluid cooling on both sides. I use the driver’s side for my trans. Not sure if there are differences from what is on the passenger side, but I believe the 6.2 had engine oil ran to the passenger side.
 

Craig 85

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I had a 730 in my '79 K15 (stock 350/TH-350/A/C). No issues with over heating. The capped fitting you see should have had a heater hose going to it. The PO had the hoses hooked up wrong. It's not pictured very well, but the top plate for the radiator support was flat.

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AuroraGirl

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The radiator was missing when I bought the truck. The radiator support has three spots to mount radiators of different lengths (side to side).

The 6.2 radiator had the trans cooling lines on the opposite side if I remember right. The old cooler lines I removed ran under the motor to the drivers side. I bought a standard cooling line set for the SBC.
I think of the main 3 radiators(to my understanding) were small block, big block, diesel. The big block radiator was given with sbc optioned for more cooling, AC. my 78 had a big block radiator, as they say. but it had ac and a 400, a 400 gets steamy, and trans cooler line to it, and a towing package. the regular radiator probably had more than one variety, some with different number of cores. a manual with no AC needed less than an auto with AC, but obv the overkill of the two wouldnt hurt the first. the diesel radiator was just big.
then there is the rare 2wd 454 radiator, but its far from common.

My 1980 manual makes me think this info, too. fan shrouds and support plates and brackets and rubber isolators imply a similar picture.
 

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I had a 730 in my '79 K15 (stock 350/TH-350/A/C). No issues with over heating. The capped fitting you see should have had a heater hose going to it. The PO had the hoses hooked up wrong. It's not pictured very well, but the top plate for the radiator support was flat.

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I was leaning towards the 730 radiator.

Swapping from a diesel to a gas has been a bit of a pain, finding SBC brackets, radiators, and a few other things.
 

75gmck25

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It’s more complicated than just three radiator sizes, and the choices varied over the years. For example, the #730 is a 4 row 19” tall core, vs. the #161 3 row 17” core that was used for HD cooling in my ‘75 K25.

You can fit most sizes in your truck if you get the matching upper brackets and the upper and lower rubber inserts. I used a Jegs Champion aluminum 3 row radiator (161 size) in my truck and it cools really well. I also have a Stewart Stage 1 high flow water pump, Stewart 195 degree high flow thermostat, and a Hayden severe duty fan clutch with an OEM metal fan and shroud.

Another challenge is to make sure your temp sensor and dash gauge are matched. The sensor used in my ‘75 truck would have a very different resistance profile than one for your ‘85. The original GM Delco sensor for my ‘75 is no longer available, so I had to try other options.

I installed a separate mechanical temp gauge and then started looking for the sensor to make the stock gauge read right. With my current sensor and gauge it shows just above 1/4 scale at about 190 degrees, and mid scale is about 205 degrees. I decided to stick with that choice.

Bruce
 

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It’s more complicated than just three radiator sizes, and the choices varied over the years. For example, the #730 is a 4 row 19” tall core, vs. the #161 3 row 17” core that was used for HD cooling in my ‘75 K25.

You can fit most sizes in your truck if you get the matching upper brackets and the upper and lower rubber inserts. I used a Jegs Champion aluminum 3 row radiator (161 size) in my truck and it cools really well. I also have a Stewart Stage 1 high flow water pump, Stewart 195 degree high flow thermostat, and a Hayden severe duty fan clutch with an OEM metal fan and shroud.

Another challenge is to make sure your temp sensor and dash gauge are matched. The sensor used in my ‘75 truck would have a very different resistance profile than one for your ‘85. The original GM Delco sensor for my ‘75 is no longer available, so I had to try other options.

I installed a separate mechanical temp gauge and then started looking for the sensor to make the stock gauge read right. With my current sensor and gauge it shows just above 1/4 scale at about 190 degrees, and mid scale is about 205 degrees. I decided to stick with that choice.

Bruce

I agree on the different sizes. I have a 17" core but it's way to short (top to bottom) for the support. I'll need the 19" core. The 730 seems to have the right specs. Still searching "measurement spec" on the 730 and 716.
 

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It’s more complicated than just three radiator sizes, and the choices varied over the years. For example, the #730 is a 4 row 19” tall core, vs. the #161 3 row 17” core that was used for HD cooling in my ‘75 K25.

You can fit most sizes in your truck if you get the matching upper brackets and the upper and lower rubber inserts. I used a Jegs Champion aluminum 3 row radiator (161 size) in my truck and it cools really well. I also have a Stewart Stage 1 high flow water pump, Stewart 195 degree high flow thermostat, and a Hayden severe duty fan clutch with an OEM metal fan and shroud.

Another challenge is to make sure your temp sensor and dash gauge are matched. The sensor used in my ‘75 truck would have a very different resistance profile than one for your ‘85. The original GM Delco sensor for my ‘75 is no longer available, so I had to try other options.

I installed a separate mechanical temp gauge and then started looking for the sensor to make the stock gauge read right. With my current sensor and gauge it shows just above 1/4 scale at about 190 degrees, and mid scale is about 205 degrees. I decided to stick with that choice.

Bruce
i meant it more as three main categories, with options that changed over years to fill that roll for each model. its more a general thing.
 

75gmck25

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Right.

It seems GM only allowed a few choices for some parts (alternators, water pumps, etc.), but had a large number of variations over the years for other parts. Whenever someone posts a question related to "what would fit" or "how do I fix it" they should ensure they provide the year and other info for the truck. One of my favorites is general questions about Quadrajets, since you will find there were literally hundreds of variations over the years, and the pieces and parts are extremely specific. Just read through Cliff Ruggles Quadrajet repair book and try to figure out which parts of the book apply to your carburetor.

Bruce
 

80BrownK10

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The radiator was missing when I bought the truck. The radiator support has three spots to mount radiators of different lengths (side to side).

The 6.2 radiator had the trans cooling lines on the opposite side if I remember right. The old cooler lines I removed ran under the motor to the drivers side. I bought a standard cooling line set for the SBC.
Lines is not a big deal, you could just put a nipple in the radiator and run trans cooler line to the other side .
 

AuroraGirl

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Right.

It seems GM only allowed a few choices for some parts (alternators, water pumps, etc.), but had a large number of variations over the years for other parts. Whenever someone posts a question related to "what would fit" or "how do I fix it" they should ensure they provide the year and other info for the truck. One of my favorites is general questions about Quadrajets, since you will find there were literally hundreds of variations over the years, and the pieces and parts are extremely specific. Just read through Cliff Ruggles Quadrajet repair book and try to figure out which parts of the book apply to your carburetor.

Bruce
yes, which is actually something i learned when i had asked in the past about BOP vs Chevy if there was a main thing. which their wasnt, EXCEPT that passenger cars did different fuel filter/inlet setup for a longer time than trucks, having a break for a while. so while i could bolt up, i would need to change the fuel line or plumb it etc
 

Craig 85

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Still searching "measurement spec" on the 730 and 716.

Here the info from Summit Racing. The bigger radiator is cheaper.

716 - $166.99
Inlet Location:Upper driver side
Outlet Location:Lower passenger side
Core Width (in):28.250 in.
Core Height (in):19.313 in.
Core Thickness (in):1.250 in.
Row Quantity:1
Transmission Cooler:Yes
Inlet Size:1 5/16 in.
Outlet Size:1 9/16 in.

730 - $132.99
Inlet Location:Upper driver side
Outlet Location:Lower passenger side
Core Width (in):28.375 in.
Core Height (in):20.250 in.
Core Thickness (in):2.250 in.
Row Quantity:2
Inlet Size:1 5/16 in.
Outlet Size:1 9/16 in.
 

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