Minor update while I wait on tube (grumble)
Had planned to use an off the shelf Toyota rear driveline disconnect but after some research I found that the Toyota stuff was 1.09" dia which is smaller than even the VW splines so I ditched that idea.
Grabbed a rotted out Dodge 2nd gen front 60 for $150 this week and am pillaging it for parts.
The yoke shaft will get a 1480 to 1410 conversion joint and and 1410 yoke flange that will bolt to my 8.8 pinion flange assembly.
The seal surface on the coarse spline end of that shaft is a hair over 1.875 and the splines are a hair under 1.875 - will have a buddy turn that down so a 1.875 pillow block slides right over.
The other shaft and the pinion will get cut up and somehow turned to match the ID of a standard piece of DOM, will defer to my machinist on the best method to accomplish that. Cut tube to length needed and weld together. 1.25 flange bearing should slip right over the outer bearing section of the pinion. Splines will hang out the back of the chassis, standard D60 yoke will bolt on sandwiching the flange bearing and keeping that shaft in place.
Reuse Dodge fork mechanism housing with a cable shifter setup.
Lots of claptrap. I started researching 1.8T to GM trans adapters as a backup
It'll be fine! I think.