The puke tank will work at any level, as long as the line going into it is below the level of the coolant in the tank. I've used a 1-quart paint thinner can with a piece of copper tubing soldered into the screw-on cap, and a small vent hole drilled into the top of the can. Run a rubber hose from the end of the puke tube to the tubing in the can. Fill the can about 1/3 with coolant, and make the copper tube go to within about 1/2" of the bottom of the can. When the radiator pukes a little fluid, the can catches it, and it siphons back into the radiator when the engine cools down and creates a vacuum in the cooling system. I mounted the can to the core support with a piece of sheet metal soldered to the can, and a couple of sheet metal screws into the core support. Paint everything flat black, and it looks original. Be sure the cap you install has a spring-loaded vent valve that will allow vacuum to refill the radiator. A 7# cap should be plenty of pressure without damaging the radiator or heater.
Jerry
