Was able to get some shots, but hard to get the whole system.
Here is the transisiton they made from the A coil to the supply plenum. Just below is the main return air box that runs parallel to the unit to the far end where the main return air plennum is. (don't know why the house was originally built that way and plumbed, but have to deal with it. Seems to help keep the motor noises down quite a bit, if nothing else.
Here is one that shows an overview of the completed system. The shiny stuf is new supply run and a larger return. The pipe coming just under the furnace is a huge supply line going into the living room and branching off to kitchen area downstream.
The center is the furnace (on it's side) to the left is the A-coil and supply plennum. To the right of the furnace is the main return air attached to the new large air filter.
This pic shows one of 3 VERY large supply lines with a smaller Y takeoff to another smaller duct.
I have NO complaints with the system performance! It cools down quickly and the fan starts slow, ramps up to a higher speed for 4 or 5 minutes, then ramps down to just barely blowing. I surmise this is the way it is supposed to work.......