Idk what you mean by that..the 3 core is thicker, not physically wider or taller, so the surface area..at least frontal area is the same. Its harder for air to pass through the thicker radiator at slower speeds. Imagine putting a piece of netting in front of your mouth and sucking. Then double or tripple that and its gets harder to suck air through. Bad comparison but still.
My autozone radiator is in great shape still. So ill be running it until I find a reason not to.
And I have the condensor up front which will actually now be removed..compressor kicked up the bucket in the past few days. Ditching all that stuff to clean up the bay. Outside of that i have a powersteering cooler and may throw up a oil cooler, haven't decided if I really need 1 yet. May just add a remote oil filter to hold a little more oil and be done with it.
You probably don't need a multi-core radiator. There are a ton of variables involved, but technically, multi-core radiators do have a greater surface area (not frontal area). A 2-core unit theoretically has double the surface area in the tubes and fins, offering the liquid double the opportunity to dissipate heat into the air. Fin design and fin density have a lot to do with airflow through the unit, but the engineers have done this homework for you more often than not.
For wheeling in 4-Low, where you've got low speeds plus relatively high engine loads, an electric fan with a toggle switch solves the problem of low speed/high load air flow through the radiator. Though, I'm still using my stock fan, with damaged blades and no shroud - and it hasn't gotten hot on me yet (I use most of the tricks in my list below...otherwise, I would be running hot when wheeling).
Some multi-core applications assume you're going to be using an upgraded fan and water pump, so that's something to look out for. That's the other thing to think about too with multiple cores is that your stock water pump may not be enough to circulate coolant through it, reducing the convection cooling in the system and defeating the purpose of the upgrade to a certain extent.
But anyway...your stock radiator with a couple little mods for efficiency is probably more than adequate. Here's my engine cooling list...
1) A clean, OE style radiator...no scaling or buildup internally.
2) Fully shrouded.
3) The Ford fan is a great idea. I've yet to install mine on the truck though. My to-do list is huge! One of these days...
4) Water Wetter or similar, at least 50% water (here in SoCal, I don't see anything below 32 degrees but a few times a year...I am currently running 90% water).
5) Hood vents...I can't tell you what a huge difference this made, just in radiant heat alone you can feel the difference in the amount of heat coming off the radiator plain as day.
6) Oil cooler...do it. First off, oil temperature is directly related to engine life. Second, if you cool one thing, the other things will also be cooled passively because you're reducing the thermal load...if you cool your oil, your coolant will be affected, and vice versa...same as your transmission if you had an automatic. For as cheap as it is (under $16 for an OEM cooler at a junkyard, and some hose) it's a no-brainer. Especially if you're in the desert.
7) You can run sans t-stat in the summer to increase coolant flow a little. It might take another 60-90 seconds to get up to running temperature (not a big deal).
...unless you're putting out 400% of the factory horsepower at high RPM's in summer heat on a regular basis, this is going to get the job done, and increase the temperature ceiling by a huge margin allowing your engine to work harder and longer while staying in the optimum temperature range (around 195-200 degrees is ideal for most engines).