Correct me if I'm wrong but if the thermostat is not opening, the top hose should not be hot because it's not passing water from the engine into the radiator. It seems to me, that the hot top/ cold bottom hoses indicate a complete lack of circulation. (If the temp is really that different.) If the radiator was blocked, the water pump would starve and might or might not, make some kind of noise in complaint. You wouldn't know about a blockage if you pop the cap and check the water level with the engine off. However, if you start the car with the rad cap off and the rad is clogged, you should have water running out of the top of the radiator because it can't get back to the bottom of the radiator.
Did you make sure that the thermostat is in right side up? If the expansion element is facing up into the gooseneck, it will take a long time to get hot enough to open. If not that, are you sure that the water pump is functioning correctly? Before I did anything else, I would pull the rad cap and start the car. Make sure that the water is flowing (Water pump ok) If not flowing but not overflowing, check t-stat for proper installation. If so, spend more time looking at pump.
Just a thought.