Okay.. not as much progress as I would like to have, but winter has been furious on it's way out. Finally got one rear airbag mounted, all ready to go.
Here you can see how the 45 degree elbow fitting sticks up inside the frame.
And finally, the tool of the trade. I wouldn't want to perform this work with the truck together and sitting upright. It was enough of a pain getting these holes drilled with a bare frame flipped upside down!
I'll take some 'in progress' pics when I get to work on the other side.