Dreaded radiator sizes

[eherbaugh]

Good morning. My 85 c10 that originally came with a 305(now has a 350) has a cheap off brand aluminum radiator with two electric fans and a trans cooler mounted to the front. This thing is laying on a piece of plywood they used one of the factory upper brackets and Jerry rigged the other size. Is there a 100% way to identify the correct size radiator that came from the factory? I’m going to get a new aluminum radiator and trying to make sure that it will work with the factory mounts. Thank you all in advance.

 

[geolee]

I have a aluminum champion radiator and it works with the factory mounts and was decent price back when i bought it

 

[75gmck25]

I have had some success with going to the Rockauto or LMC web sites and looking at the radiator options and sizes for the year of the truck. Based on that you may be able to determine the size you need/want. In some years there were different height/width dimensions offered, and in all years there are one, two and three row choices.

Based on RockAuto - In 1985 they offered several radiators that were 28 1/4" wide, and either 17" or 19" height. Most are 1 1/4" thick, but the OEM 3 row shows 2.17" thickness.

The top of the radiator is held by an L-shaped metal piece (with rubber inserts?) that sits down on top of it. That piece is sized differently in height for different radiator heights.
The bottom of the radiator sits in a rubber saddle that is designed to mold/snap onto the bottom of the radiator, and then that saddle rests in a metal support under the radiator. If the PO disposed of those rubber pieces, you want to get new ones. You could probably make a generic piece of rubber work, but that OEM saddle is simple and effective. This is what I mean. https://www.rockauto.com/en/moreinfo.php?pk=13221793&cc=1143357&pt=1000830&jsn=643&_nck=8LVLUxTaILBT+tLxkg8+3Ag7/0bbOhvn7P3rkFbL809YNOHQDmNBznFtdYfbcEUriQ0mcmy/TcWfcbfHTjxSwndfe2chgzy88liHO2MoAcp7wW7lek5DxawTLSg/DpYU6glXntEIULqpvdpyfo/a/bvkad+R8NiiTIS41j5R+GQlNcMakU3WZQ9NPMQUFjthl14gMzyNQriVEn3ctPlMNJaXG7477xVmQ6DLPa01JX72UgTg3+uI3/74ZsJxQTv57Q2wnsuy+OLJGf6bXrYx48sa5ngXKPxC2YX3bbfdjNY=

Most SBC radiators have a fitting near the top of the driver's side for the heater hose return. If you have an automatic transmission you want to ensure the radiator includes the transmission cooler and fittings.

 

[eherbaugh]

Thanks for the info. I do have the right side flat top L shaped mount with the rubber. I will will have to order the right side and the lower rubber isolators. As far as height it looks like I can just measure from where the bottom isolators rest to the bottom of the top bracket. Thanks agin def helpful information

 

[75gmck25]

AFAIK, the height listed in the specs is measured as the height of the core (only the finned area).

I bought a Champion all aluminum radiator from Jegs for my ‘75 GMC with 350 and it works really well. I also have the factory shroud, metal bladed fan, and a severe duty fan clutch. It keeps temps under about 200 even idling in traffic with A/C running.

 

[87SQRBDY]

I bought a champion aluminum radiator from champion and they said it would fit my 1987 Chevrolet R10, but it doesn't. The top metal hold down brackets don't line up and the fill cap get covered by the metal hold down. Tried to go through their return policy and got ghosted. Thought i had more photos, but must have deleted them.

 

[Tyger13us]

I put a Big Block 4 core truck radiator in mine,, shroud and the flat plate 1 piece style radiator top support. works pretty good.

Im getting ready to put a 82 c10 diesel radiator with the built in oil cooler and the trans cooler connections on the other side.
trying to keep the oil temp down....

I had one of them Aluminum radiators, nope, wouldnt keep it cool no matter what i tryed.
electric fans plus a clutch 7 blade fan off a diesel. still wouldnt stay cool.

 

[AuroraGirl]

I put a Big Block 4 core truck radiator in mine,, shroud and the flat plate 1 piece style radiator top support. works pretty good.

Im getting ready to put a 82 c10 diesel radiator with the built in oil cooler and the trans cooler connections on the other side.
trying to keep the oil temp down....

I had one of them Aluminum radiators, nope, wouldnt keep it cool no matter what i tryed.
electric fans plus a clutch 7 blade fan off a diesel. still wouldnt stay cool.

something wasnt working then, unless you mean the trans/engine oil rather than engine coolant. the coolers can be restricted or there is corrosion, the lines could be restricted. there might be air, etc

 

[BlazerBill]

I bought a Cold Case radiator for my ‘83 K5. I had to heavily modify the upper metal mounts to hold the radiator and upper fan shroud in place.

 

[David King]

Might want to check in with your local Radiator/A-C shop. One thing you may encounter is that they originally came with a 3 row core. That has all changed. You will probably end up with a single row core. Take your old core with you if you choose this option.

 

[edgephoto]

If you want the original part number for your truck I would need to know, A/C or not, Auto or manual gearbox, and ideally what gear ratio in the diff.

 

[JBswth]

Good morning. My 85 c10 that originally came with a 305(now has a 350) has a cheap off brand aluminum radiator with two electric fans and a trans cooler mounted to the front. This thing is laying on a piece of plywood they used one of the factory upper brackets and Jerry rigged the other size. Is there a 100% way to identify the correct size radiator that came from the factory? I’m going to get a new aluminum radiator and trying to make sure that it will work with the factory mounts. Thank you all in advance.

 

[JBswth]

Just order a factory-style radiator for a truck with a 350 and AC, and you will be good to go. If you want a Desert Cooler, order a radiator for a truck with the 454 and replace the top mount.

 

[eherbaugh]

Just order a factory-style radiator for a truck with a 350 and AC, and you will be good to go. If you want a Desert Cooler, order a radiator for a truck with the 454 and replace the top mount.

Good idea. Thanks

 

[Broken85]

I bought a Cold Case radiator for my ‘83 K5. I had to heavily modify the upper metal mounts to hold the radiator and upper fan shroud in place.

I did this as well on my 85 K10. Cold Case is a solid radiator. I modified the original brackets and then 3D printed new inserts for the top and bottom. I went with electric fans so I didn’t have to worry about the shroud, but that would have been a chore

Here is the measurement you need. There is a tall one and a shorter one available. If yours uses the same brackets as mine, it’s the tall one. The short ones (I think they are 1.5” shorter) were for 6cylinders I think. The other deciding factor is if it has factory air or not. My truck came stock with a 305 and AC.

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