I think its will strong enough, here are some much stronger turbo BMW's using shortened halfshafts without any problem.

Now i dont know exactly, if i remember the right side is 3cm, and the left is 2cm shorter, or vica versa. first, we pulled that tube to the shafts, and joining the two half of the halfshafts (

). Welding together the two shafts, and machining down the weld even the halfshaft's surface. After pulled over the "tube", and welded around, thats all. Tomorrow i make a test fit to make sure its ok, and if we make the welding, i'll take pic's. Sorry about the english, hope its ok.
