03 ford expedition 4.5, when the truck has been sitting over night after the engine warms up it takes a long time for the heat to actually feel warm coming out of the vents

Consider back-flushing the heater core and, possibly, the whole cooling system. If you haven't changed the coolant every 30,000 miles, there may be corrosion in the heater core. Refill with a 50/50 mixture of Zerex G-05 (HOAT) and distilled water. Also, check/replace the thermostat.