CDonaldson,
Thanks for the description, very interesting. My truck is NV5600 2WD QC SB and it doesn't look like a one pc exists for this combo. Not having the probelm, and my has been a daily driver 118,000 miles just recently started towing my 9,000 lb trailer couple time a year. I did notice that the trans rear seal is looking a bit wet, need to R&R.
Gary, there was no application for mine either. I had to use one for an 06 Mega Cab with a G56 trans. Then I had to have it shortened 1. 5" and balanced. You should be able to use something similar or, just go with a full custom build.