Hello I will answer your question,
The short answer is yes the instrument panel does get removed to replace the heater core in a B2300. If you have the year I can provide specific information on how to do this and to replace the heater core
The optional information did not show up until just now. Sorry for making you state it twice the webmaster keeps promising to fix this bug but no joy yet.
To remove the dash:
Removal and Installation
Removal NotesSteering Column Opening Cover:Remove two screws and pull cover straight out to release clips.Dashboard:
To remove the heater core:
Remove the plenum chamber
Remove the screws and remove the heater core cover
To remove the heater case you will have to discharge the AC system and remove the evaporator case as there are nuts for the heater case behind it
If this is the information you asked for please ACCEPT this answer. If not please ask
Welcome to the eternal question of automotive technicians all over the world "what was the engineer thinking and why does he hate me so much" LOL!!! You can get a shop to recover the AC system and recharge it properly when you are done with the core. They should not charge much to do this.
When you accept the answer a dialog will open for bonus and feedback to be entered as you determine what my service was worth to you.
If you have questions please ask