About how much to have heater core replaced?

[88AriesLEwagon]

Mine isnt leaking.It doesnt have any coolant in it at all.The car will not be driven until everything on it that needs attention is replaced.Currently the engine is torn down to the short block.It had a bad head gasket,but I am going with a rebuilt head,and new rings/bearings/oil pump...all that stuff.When it gets put all back together,I want it to run as well as a 2.2 can...

[Silverbeard]

Leaks will start off small and can be stopped for a while with a rad stop leak additive, which will keep you going until you are ready to do something with it.
First thing you might notice is that when on defrost, it will fog the widndshield leaving a residue behind, if you have A/C you may notice dripping from the condenser drain or without, it may drip out of the heater ducts. Mine did all 3 things at verious times before I got it fixed.

Now to ask the experts a question:
Some time after the repair was done I actually had to use the defrost and there was no air coming out. It appears that there was no duct work left from the heater box to the dash. Apparently the guy doing the repair neglected to tell anyone it had disintegreated, as I was told it was some kind of fiberous material that deteriorates with age.
Has anyone else had this experience or know if the duct work is avaiable? The shop was getting some flexible stuff that could be fashioned to hook it up again and the last time I went in they could not find it so I will try them again in spring when I have it out of storage.

Hope I have helped a bit and that you can help me.

Thanks
Martin