4x4's ok, extra dryer why? what's up with the ductwork
That looks great but very rarely do I come across an attic with enough hieght to use something like that. Even my help couldn't complain about getting mastic on thier hands trying to seal the bottom of the unit....Awwww!! lol
I am in the south east swamp. South Carolina. A lot of homes here are old with very low and wide with a low roof line. Usually I build a 2x4 platform with 3/8 plywood, set it on top of the truss and screw it down. I use to use the old metal pan with 4 in. risers but have recently started using plastic secondary. All this usually leaves me about 6 to 8 in. above the unit. I try to talk them into a pkg. whenever I can.I dont get many new installs, mostly changeouts.
Looks like you've got a lot of room to play in the snow!
Factory installed LL drier, so the second isn't needed.
As for the 4x4's, I'm pretty sure your local American Standard supply house carries the styrofoam blocks that are 4 feet long, 4"x4".