1986 C10 heater core

I have a 1986 C10 that needs a heater core. As far as I can tell, I have everything ready to pull the box out, except for the one bolt on the bottom right side. Looking under the hood, I can see a plastic(?) push
in connector of some sort in the area.Truck has a/c so that is not very easy to get at. Any advice will be much appreciated. Thanks, Larry
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.