Redrilling the axles is only viable if you’ve got enough material on the outside of the register to move the stud out .125. There should be at BARE MINIMUM 1.5 bolt diameters from the edge of the hole to the outside diameter of the flange, with 2 bolt diameters preferred for tear-out strength. I still recommend a set of new Dutchman axles for the $400 or so (last time I checked) because stronger material and the probable age of your existing axle shafts. You can pull a shaft to tell, but if your at 1/2 spline of twist at the end of the shaft, they’re pretty well done.
