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86 k5 auto chev 305 Radiator question

Justin Fleming

Justin Fleming

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Hello

I have a stock 1986 k5 blazer with a 305 (terd) with auto trans that I use for snow plowing. Currently the radiator is on its last leg and I am interrested in upgrading it to a bigger radiator. I remeber in my dads 1978 he had this huge 4 core. Does anyone know what make/model I can use for a radiator that is bigger than the stock one I have today. I am hopeing for something that bolts right in with minimal modifications. I do run the fan shroud and I do have the trans lines pluged on the radiator as I have a external cooler.

thanks
 
I started looking for a radiator for my 84 myself 350/700R4. I live where it typically is in the upper teens or low 20ies in winter for a bit,then summer hits and blastin thru fresno or Carrizo plains nat monument it typically hits 110+ easy. Ive never had problems with any of my other trucks with the stock type "HD" radiator which is a all metal 2 row. In my search for a replacement I was kinda surprised to now see whats was listed as "non HD" or "standard trans only" as a single row aluminum with plastic tanks. I have yet to find any who offers a off the shelf 3 or 4 row however a good radiatior shop should ba able to whip one up for a price. I would think if your plowin snow you wouldent need anything but a good trans cooler and 2 row. Just my $.02
 
I put a Go-Dan (GDI) radiator in my 88 about 6 years ago. I think the application was for a GM ambulance duty, or something like that. The part # is 43-3730.

It is about twice as thick. IIRC it used the same upper and lower hoses, tranny connections, but you need to be a little creative to mount it. It's thicker so upper and lower mounts need to be modified, and I ditched the fan shroud. You might be able to find a shroud from a bb chevy if you need to keep it.

I was going to eventually get a shroud, but ended up going with electric fans...
 
Take your old radiator into a local rad shop and tell them to turn it into a four core. It'll move more water and stay cooler and they'll probably give you a good price when compared to going with a Griffin or something like that. Also use a huge tranny cooler (If your truck is an automatic) mounted in front of the rad if your plowing as things get hot when your constantly going back and forth
 
it's kinda interesting that people still say to take the radiators to a radiator shop to have work done to them...

i tried that awhile back, and a few times since then with some other vehicles, and they told me it was just cheaper to buy a brand new unit,,,which it was,,,AND has a lifetime warranty, (no, not through Autozone)

I paid right around $150 or so for the one in my Burb, it's a 4 core, and about $135 or so for the one in my '94 half ton pick up, which originally came with a single row radiator, they sold me the heavy duty cooling 2 row "Maxi-cool" for that price. "Maxi-cool" i found out are that the cooling tubes are slightly wider than the factory style units, so instead of having two 2/8 inch or so wide tubes, i have dual 1/2" tubes running through it.

middle of summer, 120 degree temps, with the AC blowin on max, and it rides right at the t-stat, all the time.

the Burb still has the regular sized tubes though, but is a 4 row.

Be aware though, if you are going from a 3 row to a 4 row, there will be some mods you'll have to do, like different radiator mounts and the fan shroud will have to be modified to fit correctly.

Honestly, in your area, i personally believe that a new stock radiator, will do you just fine., and if you want alittle extra cooling help, opt for the heavy duty cooling fan clutch, also have this on the Burb.
 
Im taking mine to a shop where it cost me $75 to rod it out and resolder if its rebuildable. Granted its cheaper typically to just throw it away and buy a new one but thats part of todays problem as I see things. Nobody knows how to do **** anymore but swap parts,no more fixin things and all the new things are made overseas. It will catch up one of theses days... or shall I say it has finally.
 
4 cores made for the trucks were wider, and require modified or different upper radiator bracketry, and a different fan shroud.

A 3 core is going to be plenty for a 305. Or you can go to an aluminum one.
 
dyeager535 said:
4 cores made for the trucks were wider, and require modified or different upper radiator bracketry, and a different fan shroud.

A 3 core is going to be plenty for a 305. Or you can go to an aluminum one.
Click to expand...

I plan to put a new 350 in the old girl during christmas break so I am looking ahead to the future also.....

thanks for the help
 
I would call a parts store, or check online, and say you have the exact same truck you do have, except substitute the 5L engine with 5.7. Only difference should be auto vs. manual transmission, and that (used to at least) be cooling fittings. From what I've seen, anymore they are all made with the fittings, just plugged if manual trans.

A 3 core is generally enough for most all, but when you add things like larger engines, sub-par cooling systems, higher ambient temps, inadequate fans or shrouds, crawling, automatic transmissions, and much, much more (lol) you CAN start to tax the stock smaller radiators.

But generally, poor cooling is a result of cooling system neglect, typically in the radiator itself.

Here is some reading, if you want to study up on it a bit:

http://www.stewartcomponents.com/tech_tips/Tech_Tips_5.htm
 
A few years ago I replaced the factory radiator with a 4 core. I got it at Autozone for about $150. I ordered new upper brackets and rubber feet from LMC for a 4 core (454) radiator. I also mounted a 1/8 inch aluminum plate behind the radiator and cut out two 15" holes for electric fans to mount. When the sensor turns the fans on you can see the temp guage drop quickly. A 4 core radiator quickly removes excessive engine heat.
 
Mike D said:
A few years ago I replaced the factory radiator with a 4 core. I got it at Autozone for about $150. I ordered new upper brackets and rubber feet from LMC for a 4 core (454) radiator. I also mounted a 1/8 inch aluminum plate behind the radiator and cut out two 15" holes for electric fans to mount. When the sensor turns the fans on you can see the temp guage drop quickly. A 4 core radiator quickly removes excessive engine heat.
Click to expand...

So how has that rad held up so far? A local yard wants $75 AND my old 4 core... that thing weighs a ton.
 
just buy another stock one and get a heavy cooling fan clutch. i been running this set up for years with a undergeared over powered fullsize, towing and offroading in 100degree+ days and never over heated yet
 
To USSKOVAL, It has been 6 years since I replaced the radiator. So far no problems. I also use my 1981 K20 to haul 2 tons of limestone for my driveway ( 5 hauls per day, twice a year ). The original radiator would overheat my 350 when hauling limestone.
 
I just run the 3 core replacement for HD w/AC . Az summer it stays just above thermostat , even in traffic with the AC on on a 115 degree day .
 
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