[G.M.]

Hary, I have posted a hundred times the problem with MOST pressure caps on the old Fords don't seat and seal down on the bottom brass seat at the bottom of the filler neck. If the bottom of the cap don't seat you don't have the benefit of a pressure cap you just have a cap sealing on the top of the filler neck like an early style older cap. If your new cap is now seating at the bottom you can fill the radiator up to the filler neck and the water will stay there. If the temperature runs below 210 and there is no compression leaks the water will stay filled for months. I'm not sure if the depth of the bottom brass seat is a little low or if the pressure caps are a little short. On some radiators I had to add a rubber spacer to make the cap seal. Also notice in the picture how clean the radiator tubes are. These were polished by years of running Barr's heavy duty stop leak with aluminum granuals in it polishing the surface. G.M.