Here's some more links in the link below.
It's not too hard just a lot of work. If your dash is cracked now go ahead and replace it too, if not it'll be really cracked when your done.
https://www.dieseltruckresource.com/...7&postcount=21

 

i surprised myself by keeping my dash crack free. i think ill just order the dash mat anyways

 

Yes mine got changed when IT wasn't nessecary Another $1200.00 wasted! Thanks to D/D EDMTON ab!

 

So before I go to the trouble of replacing the core is there anything else to think about? I get almost no heat no matter which vents I have selected. The one thing that makes me wonder is that I can hear the coolant gurggle through the core when I start the truck with the heat on. Maybe this is a bad sign, does anyone else's truck do that? I wish I had known it was bad before making the drive back to AK...

 

you might want to try to flush your heater core if your just not getting heat. you'll need to change your heater core if you smell your antifreeze in the cab and your windshield fogs up. i've heard some people flush their heater core with CLR or something like that.

 

Definitely no antifreeze smell or fog. With 200,000 miles on the truck (and I assume on the core) do you guys think the flush would be a fix that would last very long? Some of the other sites talk about flushing old cores and they say that it generally causes the core to start leaking and then you have to replace the core anyway... I don't know about that but... I picked up a core from NAPA this morning and am just waiting for it to stop snowing or for a heated garage to fall out of the sky.

 

While your in there you should change the evap core too.