After 32 years of ownership '65 3000, '67EType and at least the last ten of trying to stop leak from radiator spigot including lapping the valve seat, and buying a new one that also leaked, a small cork bought at Ace hardware jammed into opening got it down to 2 drops an overnight. So finally decided to launch all-out war with plans to seal with solder, expoxy weld stuff etc, ended up with a stainless steel, fine thread, 1/2" dia, 1/2 inch long bolt from Ace hardware (small Ace store did not have but big store 4 mi up PCH did [tried six others home depot, PEP Boys luck]), also a plumbing dept washer, whitish plastic-like (used before and works fine). NO DROPS either car, no newspaper on garage floor at front, Jay