Jeffy, I think you are right; I think that it just was not hot enough to make it all that noticeable, as today driving to the office I did notice some heat coming from under the dash. I did think that the gasket was part of the problem, as in the housing, there are two holes: once to the thermostat that allows the coolant to go to the radiator, and one to the heater core. The gasket was blocking part of the passage to the thermostat (and thus the radiator) and sending more hot coolant to the heater core (I have to say, even though I still feel some heat coming from under the dash, it is less than before). So, I will still need to check the manifold, but now at least I am not leaking coolant through the housing, and the problem has been reduced quite a bit...
