sorry for the delay.......
the bottom edge of the cross bar is 8cm above CP3 CP4.
The first harness mount is 6cm(to center of hole) in from the upright of the roll bar, then an 11.5cm space to the center of the next harness mount center.
Both sides are set at equal dimensions.
Tho please be aware the position of the harness mounts will be dictated to by the seats you use etc.
hope this helps.
cheers
andy