no heat in car. trying to figure what to do before changing heater core and hose assembly leading to heater core. any comments would be helpful. thanks in advance

 

I am aware you requested info regarding replacing the heater core because you suspect it is restricted.
You might try disconnecting the heater hoses where convenient and try running a garden hose flow through the heater and see just how restricted it really is. Sometimes we get lucky and can flush out a lot of sediment and circulation will improve enough to get some heat, but you might keep in mind the heater core is 15+ years old and may have accumulated a lot of sediment that might not want to come out or if pressure is exceeded , what didn't leak before could become a problem and leak now. We know the price to do the job seems high, but now that you have some idea what is involved, maybe it just might be worth the cost. Never hurts to get other estimates.