I don't think I could R&R the evaporator in 3.8 hrs. I did the heater core several years ago. It's right next door to the evap. It took me two days to do the heater. I looked at the evap while I was in there and it was MORE work than the heater. Not only is the dash pretty much removed but for the evap the front fender needs to come off. Maybe it was a shortcut I decided on and it's not required but I decided that it would help.
Never memorize something you can look up.