I often wonder about cooling issues. I have the '69 cast iron Milodon pump ( the '69 and earlier are 3/4" shorter) I removed the aluminum pump for the 3/4" gain in space.
Then got the mop 756A CCRad. It's the same radiator that you have, but the bottom inlet is opposite side. 195 Flowcooler thermostat. Mopar fan and Hayden #2947 fan clutch, it fits. No shroud, yet. Fairly healthy 418, but I do have Trickflow heads. Haven't had any cooling issues so far, idling or driving.
So what's really that different? Your 360 should be cooling fine. That is what makes me wonder!
