Aviator hip and shoulder room, as well as headroom and hence passenger volume are less than the Explorer. This is probably due to additional sound insulation and padding. It is interesting to note that the cargo volume behind the third row is essentially the same for both vehicles.
I am not looking to accommodate 4' x 8' sheets as I usually get them cut to a more manageable size depending on the current project. I am more interested in knowing what the practical size limit is.
I found I had previously downloaded tech specs for the Explorer that included the following:
Cargo width, wheelhouse 48.1"
Cargo length closed – first 83.9"
Cargo length closed – second 49.8"
Cargo length closed – third 20.8"
Cargo length above floor, behind first row 78.5"
Cargo length above floor, behind second row 43.4"
Cargo length above floor, behind third row 12.7"
I'm not sure what the difference is between the two sets of lengths - perhaps due to seat-back slope.
I haven't found equivalent information for the Aviator.