Radiator Selection

[bluec10]

I've been browsing through some catalogues and I have a question about radiators.

I understand that factory radiators were selected based on the cooling needs of the particular engine in the truck. I also understand that many had autotrans coolers built in. But what difference does it make if a truck had air or not? Asked another way, what is the difference between a 4 row rad w. trans cooler in an AC truck vs. a non AC truck?

Just wondering.

[Bowtie67]

Generally 4 core radiators where used behind high performance motors, big blocks and the 400 small blocks. In most cases when you have AC your engine is under more of a load and during the hot somer days and being stuck in traffic the larger radiators worked a little better to keep things cooler. I am not 100% positive here but a 3 core radiator behind a 350 with AC is basically the stock option, the 4 core option with the 350 with AC may have been more in line with a towing package.

[jcfoote60]

I bought a 4-row from http://www.radiatorbarn.com/ for my 72 SWB 4x4. (You need to get teh 4-row brackets and rubber from someone like LMC or Brothers), but you can ge a 4-row with automatic cooler for $184.00 with free shipping from them. They are not refurbs, they are brand new. Mine keeps my 350 nice and cool. I am going to buy another for the 69 Blazer I am currently restoring. I think it's a great price and they have great customer service.

JC

[BubbaGreen]

nothing wrong with putting in 4-core radiators, but for a 350, might be overkill. Check out www.usradiator.com, the sell a hi-efficiency 3-core that will fit in place of 2/3 core radiators using the same brackets/rubbers. No need to modify the lower core support.

[bluec10]

That AC trucks need additional cooling is a given. I guess I was wondering if the AC rads had different brackets or something to allow for AC installation.

Is it just the 4 row rads that need new brackets and rubbers?

[jcfoote60]

Yes they do have to have different upper and lower brackets and rubber inserts, plus you do need to modify the lower core support (I had forgotten that). It's not a big mod, you just need to notch the lower core support lip the width of the bracket to allow it to sit flush with the core support lower section. The cut is easy, I just used a dremel tool (didn't feel like hooking up my compressor and using my cutoff tool). It was easy to do really. To give you some idea of the cooling change, the guy I bought the truck from had a std 3 core in and when he towed he overheated. His solution was an engine oil cooler...now it not only runs dead cool while towing but it no longer needs the oil cooler.

JC

[Bill Malanca]

I went scrounging at a local junk yard and found a 74/75 Olds wagen with a 4 pass cross flow radiator. I had to move the bottom tank supports over a couple inches but the tops were right on the money. My 69 was originally a 6 cyclinder so maybe thats why. The inlet and outlet location and size where perfect.I really don't think theres any difference being for a/c or non a/c other than maybe an extra pass or core. My 2 cents, Hey your in Manitoba,you shouldnt have to worry bout a/c or overhaeting.....

[bluec10]

Your're right, Manitoba summer temperatures aren't a big concern for vehicle overheating. My question was a bit academic, but...

Right now my truck has an L6/3 speed with the dinky little rad that came with that combination. In Spring I was driving at about 70 MPH for a few miles and the temp light came on. Other people with this combo have also said that the 3 speed causes the engine to rev so high at highway speeds that the thing runs hot. Maybe a 4 row is overkill, but if my little L6 runs hot, I can imagine that some of my 400 hp SB dreams will need some careful rad selection.

[junkyardjohn]

ALMOST ALL OF THE TRUCKS I'VE WORKED ON OUT HERE IN THE HIGH DESERT ARE FOUR ROW RADIATORS. MAYBE IT'S A OUT WEST, REGIONAL THING. SOME CHEVY VANS ( ALOT OUT HERE) OUT OF THE 70s & 80s CAME WITH FOUR CORE RADIATORS , AND THE BRACKETS ARE THE SAME AS IN OUR TRUCKS. THEY ARE VERY VERY PLENTIFUL. I HAVE NEVER CONSIDERED GOING ANY SMALLER. I HATE OVERHEATING. JOHN

[Rollie396]

I picked up a Griffon 4 core aluminum rad to put in front of the 400sb that'll be in my truck.It's not as purty as some,but the price was way more reasonable than the polished up ones and I've heard alot of good things about them.