Remove the air cleaner and look behind the rear of the intake manifold. There are two hoses coming from the intake, one from the top between #'s 3 and 4, and one from under the carb at the rear of the mani (S bend with different diameters on each end, IIRC). THere is a steel water line that goes from the two heater hoses behind the motor then under the exhaust mani to the water pump. Not at all fun to get to the hoses, and loss of hide is almost guaranteed.

Rent a radiator pressure tester at Autozome or Advanced, fill the radiator full, and pump it up. The leaks will be obvious...