Cool it, Dude
Nothing's worse than puking green Prestone on hot tarmac, sweating with the heater on in 100 degree heat, and trying to coax the needle on your Stewart Warner temp gauge back down to safe, all the while trapped in the sprawl of urban traffic. It happens all too often. Got a big Mopar mill? You need a serious cooling system to chill that bad boy. Start with the radiator. If heating's a problem, get the largest radiator that fits your Mopar body style. Still not enough? Go four row. Yeah, we've heard the same bogus spiel, "The air gets hotter as it goes though, so the extra rows don't help that much, blah, blah, blah." Get a good, four-row, high-efficiency core, and watch the temperature drop. You can usually use the OE tanks, brackets, and shroud; any good radiator shop should be able to hook you up.
Always run a shroud (available repopped from the usual resto sources) and finish the system with a serious viscous fan. Run the biggest fan that will fit (most OE units interchange), and mate it with a good, new, thermostatic clutch, rather than the cheaper viscous drive. Other key players for problem coolers are a balanced-flow thermostat (sometimes they really help), available from Milodon. Want more? Milodon, Edelbrock, and others carry high-flow water pumps, and aftermarket aluminum radiators are available in high capacities, but check the rating before buying. This Dart has been fitted with a 26-inch radiator, which runs framerail to framerail; a factory shroud; and a huge seven-blade thermostatic clutch fan assembly.