Glad to hear your doing it. Post some pictures if you can.

 

Hi everyone ! Well, I got the job done on Saturday July 11th. I have been really busy. It took me a total of 6 hours that is tools all put away, garbage gone etc. Arms took a beating under the hood with those stupid connectors. I did not fight with them, as in trying to open them, but trying to get them cut off! I could not cut them by hand (arthritis in arms and hands!) so I came up with the idea of using the air angle die grinder. Hey, worked slick as could be. I cut just behind the connectors so that the heater core could be pulled through the glove box. Now, on my 2002 F350 7.3 lt 4x4 the blend actuator sits on top of a black plastic mold which holds it in place. The black mold piece has to be removed in order to get the core out. That mold had 3- 5/16" or 8mm screws to be removed from the top. Once they were removed and the mold out, out slipped the heater core. CGMKCM advised me to have the foam sleeve/gasket on the new heater core. When I picked up the new core at Ford, there was no foam gasket. I removed the foam gasket delicately from the old core and used a high heat glue and put it on the new core. It worked 100%.
Under the hood, I used hose clamps to re=attach the hoses to the new heater core. Make sure you note which hose went to which core connector when you undo them at the beginning. If you forget, top hose to right core hook up. ;-)
I think that is all I can tell you about my experience doing this job. I thank all of you who gave excellent advise and a big thank you for those pictures !!! EXCELLENT !
I did take a few snaps.


The black mold that must be removed with the blend door actuator. 3 screws hold it in from the top.




The foam sleeve/gasket that I removed from old core and replaced on new one. This is the old core and it leaked across the whole bottom.




Where core sits in back of glove box all clean and waiting for new core. The bottom tray was full and then some of coolant. Big mess !




The new core in it's new house! ;-)


Next is new shocks on back and new sway bars. Then getting a friend mechanic to put in new front u-joints and hub seals. Need that tool that I do not have!! When these couple more mechanical updates are done, I have a couple surface rust spots to have taken care of and a new windshield to be put in. Then my girl is for sale. Yes, I am doing all this service work so I can turn around and sell her. My husband and I use to haul horses all over Canada and USA. We no longer do that and it is silly driving this truck to town for groceries !!! Love my truck, but not practical to keep her. But I am having fun working on her. Yesterday, she just turned over 300,000km which is about 186,400 miles.
I will probably be asking about sway bar help next ;-) THANKS AGAIN EVERYONE !

 

I found this thread to be helpful, so I'll add my experience.

It looks like access to the heater hose clips on the Excursion is even worse than the pickup. I could not get the clip apart.

I cut the inboard metal hose on the old heater core with a die grinder. Then connected the air compressor to the metal hose and blew it out so any fluid in the hoses would drain. Then I used the die grinder on the outboard heater core line from the inside, safe from having antifreeze on the carpet.

Back under the hood, I was able to pull that outboard hose through the firewall and open the clip when I could actually see it.

 

I also had trouble with those quick connectors when replacing my old heater hoses. I went back with hose clamps on the heater lines but after some sleepless nights thinking of what might happen on a long trip if one or both blew off in the middle of nowhere, USA so I purchased a set of new quick disconnects and they have been working fine.

I have two type tools and neither make it easy back against the firewall unless you have the tool that has an extension arm that keeps you from having to put your hands against the firewall. Understanding exactly how these work makes a big difference with how you approach their removal.

Nice pics and rightup though.