OK, I measured it. My swing arm is a +2". My measurements are close, not how I would normally do it but, here ya go;
from the swing arm pivot centerline its ~6" to the first skid mount, the mounts are 5"3/16" apart. Then it is 14"3/8" from the first mount, to the mount closest to the axle carrier, Those mounts are 3"5/16" apart. All are tapped to 8mm x 1.25mm Of course that is "IF" Lonestar got them right. and I don't have a lot of faith in them.
Swing arm measures 21".5" center to center.
desertR