No coolant to lower rad hose

[2001teg]

TI I beckon your help. This week I swapped my JDM TYPE R with a USDM gsr motor so I can turbo my itr and still drive my car. When I took the type r out everything worked fine. I reused the radiator, entire thermostat housing unit, the main coolanr pipe on the back of the motor, the hoses, fans throttle body ect. Now heres the problem, I now have 0 heat, and the lower rad hose isnt getting hot. I replaced the thermostat thinking it wasnt opening, wrong. I checked the water pump when the timing belt was off and it spun freely and looks relativly new. What internally could possibly cause this problem. Im not sure what happens when a water pump goes bad, so that could be a possibiliy. Is there anything else internally that could be failing. The system builds up plenty of pressure. I know that the water pump makes the coolant flow through the system so even if it was bad you would thing the coolant in the hose would still be hot. Help me out