heater problems

thank you for the info on the waterpump. took about 4hrs. now however when i turn the heater on, the car will start to overheat. if i leave the heater off i can drive the car and the temp. stays around 200. i have a 2.3 1994 sohc. i have thought of making a t piece adapter between the two hoses, going into the heater core. new therm. also, and water level fine. any suggestions.
thanks huxster:runaround:

well it turns out it is the headgasket. was just wishing it was the heater core.