I'm replacing the radiator on my 1999 4.2L f150 and I just pulled the old one out. Comparing with my new part before installing I noticed that my original is a double core while the new (purchased from Advance Auto Parts, it's a Carquest brand) one is a single core. My old radiator has a sticker with 'CU2136' on it, which after googling seems to be a Spectra CU2136.

I checked what Rock Auto says for compatible radiators and all the options on the 4.2L are single core radiators, but the bigger 4.6L and 5.4L v8 engines list the Spectra CU2136 double core.

I feel like the double core radiator will have better cooling performance, and for all I know the previous owner put it in because of heating issues which might return if I go ahead with the single core (or not, who can say really?). The double core may also handle carrying loads, hills, and towing better.

Another factor is the warranty on the Carquest is much better, as they claim 'lifetime to original purchaser' while the Spectra is just 2 years. Should I factor this into my decision? And is Advance Auto good to their word on this lifetime warranty?

There is an Advance Auto store a few minutes down the road, and Amazon can have a new CU2136 delievered in 2 days with free shipping. The price difference is within 5 bucks so that's a wash. I'm wondering if I should return my single core and get the double core radiator. What do you all think?

 

Whatever floats your boat.

If your 4.2 has overheating issues, a radiator won’t help that. The single row will do just fine. Most F150s of this generation had them and many of the “heavy duty towing package” folks got jammed by Ford way back when and got stuck with the smaller radiator before some <acronym title="Page Ranking">PR</acronym> by Ford kicked in and they started dishing out the heavy duty radiators.

Also, the “handle carrying loads, hills, and towing better” part isn’t really a function of the radiator. Even the single tow radiator has a transmission cooler in it. That part is more a function of the engine and gearing.

 

Surely the radiator must factor into it though. In my understanding carrying weight, going up hills, and towing all translate to the same thing: more load on the engine. In response to this the driver has to push the accelerator further which means more air/fuel combusted in the cylinders per unit time. That should directly increase the heat generation in the engine and that additional heat must be carried away by the coolant and expelled by the radiator. This is considering just with regards to heat and cooling of the engine, I know both radiators have transmission coolers in them.

 

You have no way to evaluate a radiator for cooling efficiency from those offered as replacements.
If you install larger cooling area, all that happens is the Thermostat opens and closes more often from the same engine produced temperatures.
The engine still runs at Thermostat controlled temperatures regardless of radiator capacity as long as the original capacity is installed as per original capacity...
Nothing is gained from thinking bigger is better..

 

I have a 2 row radiator on my 97 4.2L from previous owner. No heat related issues. Since you are replacing the radiator anyhow, why not the 2 row?