that may help others
Here's a mod i've decided to do as a case of having to
With the mods to the front end of my hilux, which include; crossover steering, rear springs in front, shock tower extensions, front crossmember 3inches higher, front shackels 3inches longer, big long rancho's, blah, blah.....the flex is superb,
but that causes a big problem
.......if both front wheels are lifted off the ground at the same time, the spline on the driveshaft just isn't long enough, which causes the front driveshaft to basically fall apart and lose drive to front wheels, and yes the driveshaft has been lengthened 
Turns out it's a common problem faced by all us hilux moddifiers
here's a video clip of what happens (Steve in his Mu) , (hope you don't mind Steve
) NOTE; R18 (Swearing in clip)
http://www.offroadexpress.co.nz/images/albums/hiriklux/another_mu_moment.mpg
I have seen shots of agricultural spline used, box section steel is another favourite, but personally I wanted something I had full confidence in, and is safe for me and my family on board, found a great site in the states and imported this;
12inches of travel, more than enough
Hopefully will get it fitted later this week at circletrack engineering here in Chch, they are the chaps the certifier likes down this way
Here's a link to the site where I purchased,
http://www.trail-gear.com/
they were excellent to deal with, goods arrived less than a week after order, although I was pissed off major with NZ couriers, they left the goods at my letterbox which is at the end of a long driveway, basically sitting on the side of the road
