I have a 1993 f-150 300 cid. New radiator and thermostat (165 i think) no heat. a little warm, but not hot. Both heater hoses are
hot. Before i chang the heater core, any suggestions?

 

Have you disconnected the hoses to the heater core and tried to run water through, to see if it is plugged? I would also ensure that the 165 degree thermostat is the correct one. Could also be the blend door.

 

what is the blend door?

 

You probably havea an air pocket somehwhere in your lines. When you last changed the fluid, did you 'burp' the hoses? Try doing this...Open your rad cover, and SLOWLY squeeze the upper hose. You might see bubbles coming out. This means you have air in your hoses, which is causing you to get no heat. Squeeze the lines, and repeat until the air is completly gone. Takes about 10 minutes, for lots of air. Good luck

jim