That print is for my conversion, but the ballscrew lengths are different than the stock screws. I'd have to dig them out to check. the X and Y anyway.
Also if you use the print, make the y axis screw length 7.000 inches not 6.750.
the extra 1/4 inch was needed for a customers mill (a grizzly i think) due to variations in the base castings. I'd leave a little extra and trim off what you don't need after a test fit. that way you'll get the most travel out of the base you have.
Later Hoss
http://www.hossmachine.com