Donny, Keoke is correct in that the drain for the block is on the drivers side under the exhaust manifold. Mine was a simple ball cock apparatus that when operated allowed water to drain from the block. To correctly drain a Healey you need to first drain the radiator, then remove the thermostat housing and all and then open the drain as described above also open the heater valve to allow coolant to escape from the heater radiator under the dash. When completely drained stick a hose with slow water pressure into the thermostat housing opening and allow to flow through the heater core and out the block. Once clear water appears close the engine block drain. Refill the engine block with a 50/50 mixture of antifreeze and distilled water all the way to the top of the thermostat housing. Now, flush the radiator with clean tap water until clear, then refill with 50/50 mix of distilled water and antifreeze until it overflows. Now start the engine and allow to heat up keeping an eye on the water temp gauge. After cooling back down check the radiator again and topoff if necessary. Restart the engine and check for any leaks, it's okay to close the heater valve now and you should be ready for another season of driving.