Has anyone ever come across a tailshaft were the yokes were at some angle to each other, other than in line or at 90 deg.?

The factory manual vl has them set out of phase by 90 degrees for some strange reason, when i got mine rebuilt the tailshaft place wanted to put it phase, well actually it is out about 3 degrees and ive never had any problems.

Yeah vl turbo manual shafts were the one exception for the rb30's, they were set at 90 deg, and I agree, the reason is very strange! I've given up trying to get an answer from GM, i can't get past the level 1 "pump number" ppl, or I get stuck in a "Albert Davies" voice menu system! 3 degrees error is ok, but at the upper limit. I suspect that the reason you have that error is because the cv joint for the turbo shaft is 25 spline [na cv is 24 spline] which makes it important with the turbo cv to find the correct bolt hole alignment between the cv outer hub and the rear shaft. [6 bolt holes] One bolt hole either side of the correct hole will give an error of 1/6th of a spline which is 2.4 degrees 25 splines divided by 6 bolt holes = 4 1/6th splines per bolt hole. 360 deg. divided by 25 splines = 14.4 deg. per spline, divided by 6 = 2.4 deg. per 1/6th of a spline, or per bolt hole position. It may also be [at least] desirable then, to not use an 'in phase' rear shaft in place of a 90 deg. rear shaft. The bolt hole positions relative to the yoke at the diff end may well be different and give a 'half a bolt hole' error which cannot be corrected, though this would be a small error of only 1.2 deg. I'm yet to check that out. Some original photos have not been recovered yet.