Really? Where and by whom?
The stock front joint is not serviced from any source. I queried Dynotech back in 98 about sourcing a new front joint, and it was NLA even back then from the source that built the shafts for GM / PAS. If the OEM supplier couldn't source the part 15 years ago, it isn't likely that it is available from any source now.
Most of the "repaired" stock SyTy front joint repairs I've seen involve substituting a slip-yoke and single 1210 series cross-style u-joint. Like this one that was on DesertSy.:
Or this 2" tube Bravada shaft that Ron Redd found in a junk yard. The front joint for the Bravada shaft IS available from Dorman. See the mentioned threads.