8 3/4 Thrust Block

I haven't contacted Dr Diff yet but planned to since I notice on the web site they will add spring perches. I had a rear once that has warped from too much welding on the housing and it would eat axle bearings for lunch! I want mine checked for straightness after all the welding is done.

On my initial inquiry I'm still stumped though. I realize the thrust block shifts to press against both axles but suppose the combined axle length was too great [or the axle tubes were a bit too short] preventing the bearings from seating fully. I just can't see proper seating of the thrust block and axles at the same time. Maybe the machining is just more precise than I imagined?