That pinion support bearing is supposedly totally obsolete. Period. Like no NOS, nobody makes a revised one, nothing.
When I pulled the pinion out of the housing, I may have said a very dirty word. Sorry Tony, I know you have virgin ears...
@woodrow spent 2.5 hours calling bearing manufacturers, bearing distributors, wholesalers, etc while I was building his tons. No luck.
There are a few options to correct this. Make a bronze bushing (like an input shaft pilot bearing) and install it where the roller bearing was. You can also bore the housing for the more common bearing.
Last option is to replace the entire rear housing assembly. Woody has a spare housing with the larger support bearing. But, replicating his 4 link and coilovers mounts will be a pretty major chore. He has like 1/4" of clearance around his tires and chassis as the suspension cycles. So it would have to jigged to a very tight tolerance.