I`m looking into an aluminum radiator or a 4 core, who has the best prices. I have a new 3 core now and a high flow pump,new fan clutch, I just put on the upper air diverter panels. I`m hoping all that will keep it running below 200 or I go to a larger radiator or aluminum.
Summit has a very reasonably priced Al radiator. I was having problems with a brass/copper 4 row, switched to the Summit (Northern) Al radiator for ~$180.00 and have been great since.
I bought the direct fit Summit alum for $160 a couple of months ago for my 455. I'm staying at 160 degrees at 75-85 ambient temp with no thermostate installed.
BTW, to get 160 temps, you have to use more water and less coolant. My mix is 20% coolant, 1 1/2 bottles of water wetter, and remaining distilled water.
Also, I had to cut the shroud down a bit to get it to fit properly.
I also checked Summit and found 299.00 was the lowest price. Did you order another number other than what comes up on their application? Mine is a 68 without AC and with an automatic.