I went through the same scenario when going from the 440 to 520.

The temp would creep up on really hot days. (FL 95 plus) with the stock brass 383 radiator.

Went to an aluminum 2 row with 1" tubes that was supposed to cool it, well, it did not. It acted exactly the same.

I then went to a 4 row, no other changes, and it would stay at about 165 with a 160 stat. I then took off the clutch fan and put 2-10" pullers on it thinking the temp could be regulated with the stats on a thermostat, no Bueno, still too cool.

Currently I have one fan set at 190 with a 180 stat, the only time it kicks on is when I hit a long stop light, but, it goes right back off once the car starts rolling and gets some air across the radiator face. I have the other fan on switch for cooling between rounds.

Bottom line is, go for a 4 core, you should be just fine.