I built a boring tool several years ago that screws on to the spindle and uses a 1-9/16" end mill to bore them out. From what I remember, the Dana 70 spindles are already this size.
I bored out some Dana 44 spindles for my rear to accept 30 spline and if I remember I bored out .060 or better might have been close to .100 it was a good bit. I know I had like .020 clearance between axle OD and spindle ID. Never had any issues
Awesome thanks guys. I'm going To try .08 first and see if it allows me to clear. Then see if I need to go up from there any. As it sits with 35 spline shafts there is probably not enough room to slide a piece of paper in on one side. There is just enough space to spin the shaft freely but no wiggle