I picked up an 89 Chevy truck and used the NV3500 and one piece carbon fiber driveshaft in my 85 GMC over the summer. I had been wanting to replace ujoints. When I went to get the rear joint the parts guy told me it was a special one and it took him 15 minutes to find one that would work.

Is that not a stock setup?? I have worked on mostly 85 and 86s which were 2 piece steel driveshafts.