I have an '85 GMC with A/C. I do not want the A/C. I want to install a non A/C heater box. The one in the truck is huge. Is there a huge hole behind it? Any info would be great. Thanks! Jason
I did the reverse swap last year. Yes there is a fair sized hole behind the evap core and iirc, one next to the fan you will need to cut for the non-ac. Also, the holes for the heater core hoses are not in the same place. here's a pic that kind of shows the hole behind the evap core and here's one of non-ac, I was a little busy that weekend so I didn't get one with the heater removed, but you can see where the heater core hoses are and about where/what shape the hole is.
