by geeves » Thu Sep 08, 2016 7:32 pm
no need to change diffs. The rear driveshaft on the 2.8 has a spline into the gearbox. The driveshaft on the 3.1 has a flange similar to the diff end of the driveshaft and a spline in the front section.
If you swap the outputs on the gearbox or swap the driveshaft (easier option) then you are fine
Sanding your knuckles before starting work can help. That way you cant skin them