I fought my newly rebuilt 70 Charger 440 with a water leak dripping from the lower rad hose. Ended up being the thermostat housing leaking behind the AC compressor. Had to remove it to find the leak. They can leak from anyplace.
Loc: Lincoln Nebraska
for diagnosing you can get a tank valve from O'reillys for less than $3 & screw it into the 1/8 NPT cooling temp sender port & pump it up to 10 lbs with shop air. some dish soap in a squirt bottle will help show bubbles.
live every 24 hour block of time like it's your last day on earth