GM-GMC: heater core replacement, gmc vandura 2500, heater core replacement

Question
If possible could you give me a walk through to
remove and replace the heater core in a 1991 GMC
vandura 2500.

Thank you in advanc
e

Answer
Unfortunately, my books cover only up to 1986.

In general, on a GM product, the method depends upon whether factory air conditioning is installed.  With factory A/C, getting to the heater core involves loosening and partially removing the A/C evaporator.  Without factory A/C, the work is confined to removing part or all of the dashboard.

I am sorry that I cannot be more specific.  I have not had to replace the heater core on a GM vehicle newer than mine.