And just to add for future use...
Link to Gm Parts Direct Diagram: https://www.gmpartsdirect.com/auto-parts/1998/chevrolet/c1500/cheyenne-trim/5-7l-v8-gas-engine/hvac-cat/evaporator-and-heater-components-scat
Link to a video I found on youtube of replacing this part:
I also found a the parts diagram on GM Parts Direct. I am ordering parts number 16, 21 & 4 from the diagram. Replace that entire center box assembly. Will cost about $102 which really isnt bad for original GM parts.
Well its been a hot minute since it was thinking about this. Still never did it but when I go to do it I will defiantly take pictures of the process as I always do with things like this. Now I just didn't do it yet becasue I plan on going all out and replacing everything AC related so it will be...
Did anyone find elsewhere that had good pictures? Looking to do this and photos would greatly help! I can understand the descriptions but other source of photos or a video would be awesome! This is the best write up I have found on this topic on the web currently!