Lets Talk Radiators...

Mine is leaking so I need to put a new rad in. Any advantage to single vs dual core? I have dealer air so not sure if that is going to be a deciding factor.

Twice as much area to shed heat?

Not sure of your climate, but if you need AC your truck probably needs extra cooling.
Not the least reason that the AC condenser is shedding its heat in front of the radiator.

The only disadvantage to a larger radiator is the initial cost, and maybe a bit longer warmup. As for type, aluminum cools almost twice as well as brass/copper from what I’ve read.

No longer warmup.

The engine is the same, and the thermostat is not an on/off switch

Ok thx guys...sounds like I need a dual core. Not much price difference anyway with these old trucks.

ArdWrknTrk wrote

No longer warmup.

The engine is the same, and the thermostat is not an on/off switch

Right.  I thought about that later.  My bad.  

I bought a two row alum, works great.

My 86 Bronco came factory with a 4 row radiator and I did have some minor heating problems with it while towing on long grades. When I rebuilt the engine, I went to a local wreking yard and measured the radiator from an F250 and found it would fit in the same space as the original one. I bought the fan shroud from the 250 and then went to the local NAPA and bought the 4 core for an F250. It was a bolt in swap using the fan shroud from the F250. The radiator from the F250 was 3 inches taller and 4 inches wider making it 23% larger and the shroud was bigger also. This cured the heating problem while towing. Just a thought if you are looking for a larger cooling capacity. Keep in mind that the shroud is as important as the radiator as it makes the fan more efficient in pulling air through the whole radiator instead of just pulling it through the center where the fan sits.

Any recommendations for a good radiator brand?

There really aren't many choices left, in a 'stockish' radiator.

If you want an all welded aluminum race type I can clue you in

20 years ago I would have said Modine.
But now it's just a bunch of Visteon brands if I recall

I ordered one from RockAuto and have been happy with it. It is exactly the same as my original 1984 radiator with the one small exception that my original did not have ports for auto transmission lines. I forget what brand it is but I can look it up.

If you could, thanks.

I came across this website that showed only four brands: APDI, LKQ, One Stop Solutions, and Spectra.

Any experience with products from these brands/resellers?

Is a race-type better? I'm going to guess that aluminum is better than the old stuff, and what about the number of cores, 2/3/4?

Griffin, Ron Davis and Wizard are popular here in the north east.

Aluminum is definitely better at heat transfer than brass, but isn't easily repaired with solder.
Anodizing it black helps even more.

More cores = more fluid volume and more surface area to shed heat, but there's no reason to add cooling capacity if you don't need it.
In fact it may begin to overwhelm your thermostat if your system isn't balanced.

Engine heat output, water pump volume and flow, thermostat and radiator should work tog e ther to damp temperature oscillations.
An engine can only be optimal under certain conditions.

Running it too cold or hot will make it worse.

Vic Roma wrote

If you could, thanks.

I came across this website that showed only four brands: APDI, LKQ, One Stop Solutions, and Spectra.

Any experience with products from these brands/resellers?

Mine is a Spectra CU559 (Non-AC). It is literally identical to the old original 1984 radiator that it replaced. Link below. I've had it installed for 2 years now. No complaints so far.

https://www.rockauto.com/en/moreinfo.php?pk=271941&cc=1121443&jsn=1

Good to know. The master parts catalog references different radiators for vehicles equipped with different cooling specs, and Super A/C and Regular A/C. What is the difference in the A/Cs?

I definitely have a problem with both vehicles. I read a post on ford-trucks where Franklin2 (Dave F) wrote "A pretty smart guy I heard one time say overheating in town means a[n] airflow problem, overheating on the highway means a coolant flow problem." I think I have one of each problem. The 302 hood is too hot to touch when running and even after shut-off yet the gauge has never hit H and usually rests in the middle of C-H, and the 351 hits H on the temp gauge on the highway, always. Some good advice in the above post said to get a temp gun to know exactly what Im starting with, which I've yet to do, but I was thinking it could be a combination of  radiator, thermostat, water pump, maybe all three. The 302 has an aluminum rad from the PO, so that could be an issue, and the 351 seems to lose coolant regularly, especially noticeable after a highway run, but in an obscured way. I'm suspecting the pump is at fault, but I don't notice the outpouring/dripping/seeping of green rad fluid anywhere. That said, the front of the 351 motor is coated in a film of caked on old oil, so I will have to look harder. I cleaned it off some of the key parts with CRC Brakleen, which was very effective, but now I regret that I removed a filthy yet protective layer of rustproofing. A lot going on here, hence the myriad of questions/statements.

Pointers?

The IR thermometer is good advice.

One thing I would always do is compare upper to lower radiator hoses.
(Yes, I know rubber isn't ideal, but what is important is the temp drop across the radiator.)
Check the thermostat housing, and if yours is chrome put a piece of masking tape on it to measure.

On the 351, check for combustion byproducts in the coolant
A kit or little bottle of the fluid is a lot cheaper than an entire engine.

Does the 302 have a good tight fitting shroud on that aluminum radiator?
Does it have the stock clutch fan?

Vic, I'm sorry no one else seems to have any good ideas for you.

But I'm sure you can get your cooling problems solved.
Diagnosis is a step by step process.

Thanks, Jim.

When you write "On the 351, check for combustion byproducts in the coolant" do you mean take out the overflow pipe and check the radiator reservoir bottle for bubbling, in case there is a leaking gasket?

As for the 302...
"Does the 302 have a good tight fitting shroud on that aluminum radiator?"
I believe so. I tested the airflow through the radiator with a shop towel and it stuck to the outside of the grille, which suggests the fan is working as it should, drawing in sufficient air with all blades are intact.

"Does it have the stock clutch fan?"
I believe it does, haven't checked the fan for any engineering marks/labels, but I will do so and revert.