Classic/Antique Car Repair: Replacing heater core oon 69 Chevy pickup truck, chevy pickup truck, 69 chevy

Question
About how much labor time should it take to replace the heater core on a 69 Chevy C20 pickup truck (with air conditioning), please?  

Answer
Hi Angie;
        I never did one on a pick up but I will take a guess and i would think that it would take at least 4 hours or longer as there could be some rusted or frozen parts etc it is a job and it does take a bit of time to do a heater core. I hope I could help you.