To fully echo Erik, I also run a 20# Moroso cap, and a Howe swirl pot with an overflow tank. I have a low radiator as well, and the swirl pot makes filling the car with coolant simple.
The cap is key, because once a cap vents, you lose coolant and start a cycle of creating air bubbles that spirals into an overheating condition. My friend overheated and killed his Small Block Ford at the track and we traced it back to a bad radiator cap and bad fuel pressure regulator.. at the same time.