Hey, I don't have the part number for the UCA's, I just went to Congito's website and put my truck information in. The Trailboss axle part number is 87862071, same for both sides. It turns out the axles when I laid them down side by side from the ones I took out, the Trailboss axles were a little shorter. Which kind of makes sense since when you lift, it looks like it pulls the wheels in slightly, but I could be wrong.
No issues with my setup. I installed the Cognito's because of all the chatter online about the factory UCA's going bad with a lift. Even though it isn't much of one, I felt better and since I was in there anyway, it made it easier to do.
At least changing out the axles isn't a major job.