I was a Ford dealership steering specialist back in the seventies and 80s at a few Ford dealers. I rebuilt tons of Ford steering boxes, power steering pumps, rack and pinions, and lots of tilt steering columns in the 80s, The Thunderbird Lincoln Continental tilt column assembly is identical to the 70 Mustang lt was kind of handy when I had to rebuild my tilt column for my70 Boss last year.I took my Boss steering box apart and cleaned everything up perfectly measured all 62 balls with a micrometer and they were all perfect size with no damage, so i won't be needing to buy any. I would be real careful about putting oversized balls in that steering box the possibility of binding and how would you determine how much wear is really in there I know it's not much but it's just food for thought.Thanks, Greg Springer Seattle