I know winter is aways off, but Id still like to ask, this is a 89 F-150 4.9 engine....last winter it wasnt putting out much heat so I changed out the thermostat, flushed the radiator, and went with new antifreeze....
I also had cardboard in the grill, didnt help any there....
And I still didnt have much heat...
Does this indicate maybe time for a heater core ?.....

 

My guess is that the air is not getting directed over your heater core.

The ***** on your dash are supposed direct the airflow over the heater, via a box with some flaps in it behind the dash. Something is probably disconnected so that the air is not being sent to where it is supposed to go.

 

It definitely could be a plugged heater core.

 

Yep, if it is not the plenum and the blend doors that direct the airflow to the heater, it is almost certainly the heater core.

 

crank up the heater and see if both hoses get hot

 

Ok, Ill check that out today and see what happens...
If it is the hearter core, what kind of job would it be to replace it ?...

 

I couldn't tell you. I suppose it depends on how much crap you have to move to get to it.

My 70 Bumpside wouldn't have been any problem.

 

Is the engine getting up to its proper operating temperature? If not, verify the thermostat works.