[mongocanfly]

So if all your angles are down your working angles will be 2,2..as you showed above...so either the brackets Scoti showed or wedges should work..
if it were mine ,I would cut the floor, do a tunnel, and set the trans and diff angle at 3 deg..(personal choice)...that would get the working angle down to around 1deg..
I understand you not wanting to do a tunnel though, and what you have should work