Hello I am new here on GL.net and I just opened a topic myself in Projectbuilds that shows my personal solution to the problem how to fit late S2 or Turbo disks, hubs and callipers to a 944 NA Spindle.
http://www.germanlook.net/forums/showthread.php?t=10549
You can not use the late spindle in combination with the standard 74> super strut. The 2 mounting hole's do not line up with the hole's in the strut and the part of the spindle that goes between the 2 brackets of the strut is to thin.
So save youre money on drilling the late spindle for a speedo cable, buy a set of 944 NA spindles and let someone machine the 2 bearing bushes needed to use the late turbo hub, the bushing to mount the steeringrod on top of the spindle and the bracket to mount the caliper to the spindle.