I built them for my QC so I could run on Bonneville and was going to make some up for folks, but I've been slammed at work. I've modified the front design to hang off the back of the trans tailshaft where the two bolts for the braces go. No pics of this. Messing with putting it under the carrier bearing mount was a bad idea - that's super-sensitive to angle.
http://vtcoa.com/forums/showthread.php?t=36926&highlight=driveshaft+hoop
Someone is welcome to use my design - no patent here.Wish I had time...
I'd be down to buy one from you!