I think it's way more important, as stated, to make sure your center section is a good solid aftermarket piece.
I went 9's at 150-155 mph many times (300+) with a moser shortened stock style rear end in my 3600lb Mustang using a 31 spline Ford N case while the car was running 1.4x short times. As soon as the car started leaving harder (low 1.3x times) I broke the 31 spline Detroit Locker though the N case was still fine.
At this time I upgraded to a Strange N-Case with 35 spline axles. Broke the Lenco Billet Locker within 10 runs so I changed to a 35 spline spool. Still used the Moser un-braced rearend housing.
After 300 more passes, I changed to a fabricated braced rearend housing. The car ran a lot of 1.3x and a handful of 1.2x short times during this period. When I took the un-braced rearend out, as far as I could tell it was just fine.
Just some "data" for you to consider.