There are many ways to make your motor run cooler. Just remember that you are trying to draw heat out of the coolant which is carrying heat out of the engine. First point to keep in mind is that Antifreeze/coolant makes the motor run hotter. Running distilled water with an anti corrosion additive during the summer is a cheap modification. Antifreeze raises the boiling point of the solution and lowers the freezing point. As the liquid runs through the radiator it needs to flow fast enough to pull heat out of the engine, but slow enough to remain in the radiator where the heat is drawn out by a flow of fresh air. I have no problem cooling my .040 overbored 302W in a 65 Ranchero. I am using a FlowKooler high volume water pump, An Afco aluminum racing radiator ( 2 core aluminum crossflow ), and a Spal 14" electric puller fan. I run distilled water with anti rust additive. With a 180 degree thermostat and a Vintage air adjustable fan switch, I am able to keep the motor below 195 in the heat od summer. I am also running an aftermarket Rainbow Air A/C sytem. I run a remote tranny oil kooler as the radiator has no tranny cooling feature. If you don't want to go this route, you can get a 4 core stock style radiator and make sure you run a cooling shroud. If the motor runs hot at idle in traffic, you have inadequate air flow at low speed idle or the air is not being pulled through the radiator fast enough or high enough volume. If the temperature creeps up at highway speed, make sure you have a bottom hose with the coil spring inside. Without the spring the hose will collapse on itself at highway speed. Your fan blades need to be about an inch from the radiator face. When using a shroud make sure the blades reach at least halfway into the shroud. If you want to switch to an electric fan, use it as a puller. They come with built in shrouds and if your choice exceeds 2500 cfm , you will be pulling enough heat from the radiator. Make sure you have an overflow bottle installed and use a 16# pressure cap.One other feature to check is to make sure your raiator support wall does not leave gaps around the radiator frame. This will allow air to flow around the radiator rather than throught it. Bernoulli's Theorem. Good luck.
Walt in SoFlo