From what I could tell, the J-8622 are the two side plates and hardware that attached to the main mount shown in Kevin's picture. Below are some pictures from that same Shop Manual showing the holder in use for various differential work.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
